97911891 has 48 divisors (see below), whose sum is σ = 186720768. Its totient is φ = 47865600.

The previous prime is 97911881. The next prime is 97911899. The reversal of 97911891 is 19811979.

It is not a de Polignac number, because 97911891 - 2⁹ = 97911379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (97911899) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7626 + ... + 15936.

It is an arithmetic number, because the mean of its divisors is an integer number (3890016).

Almost surely, 2^97911891 is an apocalyptic number.

97911891 is a deficient number, since it is larger than the sum of its proper divisors (88808877).

97911891 is a wasteful number, since it uses less digits than its factorization.

97911891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8352 (or 8349 counting only the distinct ones).

The product of its digits is 40824, while the sum is 45.

The square root of 97911891 is about 9895.0437593777. The cubic root of 97911891 is about 460.9054173920.

The spelling of 97911891 in words is "ninety-seven million, nine hundred eleven thousand, eight hundred ninety-one".