661663464 has 128 divisors (see below), whose sum is σ = 2104704000. Its totient is φ = 171837120.

The previous prime is 661663447. The next prime is 661663493. The reversal of 661663464 is 464366166.

661663464 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (42).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86899 + ... + 94205.

It is an arithmetic number, because the mean of its divisors is an integer number (16443000).

Almost surely, 2^661663464 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 661663464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1052352000).

661663464 is an abundant number, since it is smaller than the sum of its proper divisors (1443040536).

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

661663464 is a wasteful number, since it uses less digits than its factorization.

661663464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7348 (or 7330 counting only the distinct ones).

The product of its digits is 373248, while the sum is 42.

The square root of 661663464 is about 25722.8199076229. The cubic root of 661663464 is about 871.3896248984.

The spelling of 661663464 in words is "six hundred sixty-one million, six hundred sixty-three thousand, four hundred sixty-four".