397191926091 has 16 divisors (see below), whose sum is σ = 542242761984. Its totient is φ = 258475524384.

The previous prime is 397191926083. The next prime is 397191926093. The reversal of 397191926091 is 190629191793.

It is not a de Polignac number, because 397191926091 - 2³ = 397191926083 is a prime.

It is a super-2 number, since 2×397191926091² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (397191926093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 750696 + ... + 1165301.

It is an arithmetic number, because the mean of its divisors is an integer number (33890172624).

Almost surely, 2^397191926091 is an apocalyptic number.

397191926091 is a deficient number, since it is larger than the sum of its proper divisors (145050835893).

397191926091 is a wasteful number, since it uses less digits than its factorization.

397191926091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1917650.

The product of its (nonzero) digits is 1653372, while the sum is 57.

The spelling of 397191926091 in words is "three hundred ninety-seven billion, one hundred ninety-one million, nine hundred twenty-six thousand, ninety-one".