661468452864 has 288 divisors, whose sum is σ = 1880014827600. Its totient is φ = 206779187200.

The previous prime is 661468452833. The next prime is 661468452871. The reversal of 661468452864 is 468254864166.

It is a junction number, because it is equal to n+sod(n) for n = 661468452798 and 661468452807.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 712021552 + ... + 712022480.

Almost surely, 2^661468452864 is an apocalyptic number.

661468452864 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661468452864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (940007413800).

661468452864 is an abundant number, since it is smaller than the sum of its proper divisors (1218546374736).

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

661468452864 is a wasteful number, since it uses less digits than its factorization.

661468452864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1389 (or 1352 counting only the distinct ones).

The product of its digits is 53084160, while the sum is 60.

The spelling of 661468452864 in words is "six hundred sixty-one billion, four hundred sixty-eight million, four hundred fifty-two thousand, eight hundred sixty-four".