661231399248 has 800 divisors, whose sum is σ = 2381434880000. Its totient is φ = 176536039680.

The previous prime is 661231399201. The next prime is 661231399259. The reversal of 661231399248 is 842993132166.

661231399248 is a `hidden beast` number, since 6 + 6 + 1 + 2 + 3 + 1 + 399 + 248 = 666.

661231399248 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×661231399248³ (a number of 36 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 661231399194 and 661231399203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 667236033 + ... + 667237023.

It is an arithmetic number, because the mean of its divisors is an integer number (2976793600).

Almost surely, 2^661231399248 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661231399248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1190717440000).

661231399248 is an abundant number, since it is smaller than the sum of its proper divisors (1720203480752).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661231399248 is a wasteful number, since it uses less digits than its factorization.

661231399248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1130 (or 1101 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The spelling of 661231399248 in words is "six hundred sixty-one billion, two hundred thirty-one million, three hundred ninety-nine thousand, two hundred forty-eight".