661138496 has 112 divisors (see below), whose sum is σ = 1436217600. Its totient is φ = 301086720.

The previous prime is 661138487. The next prime is 661138523. The reversal of 661138496 is 694831166.

It is a happy number.

It is a super-2 number, since 2×661138496² = 874208221786284032, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3322205 + ... + 3322403.

Almost surely, 2^661138496 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 661138496, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (718108800).

661138496 is an abundant number, since it is smaller than the sum of its proper divisors (775079104).

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

661138496 is a wasteful number, since it uses less digits than its factorization.

661138496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332 (or 322 counting only the distinct ones).

The product of its digits is 186624, while the sum is 44.

The square root of 661138496 is about 25712.6135583297. The cubic root of 661138496 is about 871.1591085667.

The spelling of 661138496 in words is "six hundred sixty-one million, one hundred thirty-eight thousand, four hundred ninety-six".