661832397 has 8 divisors (see below), whose sum is σ = 980492480. Its totient is φ = 441221580.

The previous prime is 661832363. The next prime is 661832411. The reversal of 661832397 is 793238166.

661832397 is a `hidden beast` number, since 6 + 618 + 3 + 23 + 9 + 7 = 666.

It is not a de Polignac number, because 661832397 - 2⁸ = 661832141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661832597) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12256129 + ... + 12256182.

It is an arithmetic number, because the mean of its divisors is an integer number (122561560).

Almost surely, 2^661832397 is an apocalyptic number.

It is an amenable number.

661832397 is a deficient number, since it is larger than the sum of its proper divisors (318660083).

661832397 is a wasteful number, since it uses less digits than its factorization.

661832397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24512320 (or 24512314 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The square root of 661832397 is about 25726.1034165689. The cubic root of 661832397 is about 871.4637783743.

The spelling of 661832397 in words is "six hundred sixty-one million, eight hundred thirty-two thousand, three hundred ninety-seven".