398921656 has 32 divisors (see below), whose sum is σ = 869328000. Its totient is φ = 168067296.

The previous prime is 398921599. The next prime is 398921659. The reversal of 398921656 is 656129893.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398921659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57066 + ... + 63673.

It is an arithmetic number, because the mean of its divisors is an integer number (27166500).

Almost surely, 2^398921656 is an apocalyptic number.

It is an amenable number.

398921656 is an abundant number, since it is smaller than the sum of its proper divisors (470406344).

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

398921656 is a wasteful number, since it uses less digits than its factorization.

398921656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120811 (or 120807 counting only the distinct ones).

The product of its digits is 699840, while the sum is 49.

The square root of 398921656 is about 19973.0232063151. The cubic root of 398921656 is about 736.1435949740.

The spelling of 398921656 in words is "three hundred ninety-eight million, nine hundred twenty-one thousand, six hundred fifty-six".