97621891 has 2 divisors, whose sum is σ = 97621892. Its totient is φ = 97621890.

The previous prime is 97621889. The next prime is 97621897. The reversal of 97621891 is 19812679.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 97621891 - 2¹ = 97621889 is a prime.

Together with 97621889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (97621897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48810945 + 48810946.

It is an arithmetic number, because the mean of its divisors is an integer number (48810946).

Almost surely, 2^97621891 is an apocalyptic number.

97621891 is a deficient number, since it is larger than the sum of its proper divisors (1).

97621891 is an equidigital number, since it uses as much as digits as its factorization.

97621891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 43.

The square root of 97621891 is about 9880.3790919175. The cubic root of 97621891 is about 460.4499236826.

The spelling of 97621891 in words is "ninety-seven million, six hundred twenty-one thousand, eight hundred ninety-one".