97661621 has 2 divisors, whose sum is σ = 97661622. Its totient is φ = 97661620.

The previous prime is 97661591. The next prime is 97661623. The reversal of 97661621 is 12616679.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97318225 + 343396 = 9865^2 + 586^2 .

It is a cyclic number.

It is not a de Polignac number, because 97661621 - 2²² = 93467317 is a prime.

Together with 97661623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97661623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48830810 + 48830811.

It is an arithmetic number, because the mean of its divisors is an integer number (48830811).

Almost surely, 2^97661621 is an apocalyptic number.

It is an amenable number.

97661621 is a deficient number, since it is larger than the sum of its proper divisors (1).

97661621 is an equidigital number, since it uses as much as digits as its factorization.

97661621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216, while the sum is 38.

The square root of 97661621 is about 9882.3894377827. The cubic root of 97661621 is about 460.5123796001.

The spelling of 97661621 in words is "ninety-seven million, six hundred sixty-one thousand, six hundred twenty-one".