91620553 has 2 divisors, whose sum is σ = 91620554. Its totient is φ = 91620552.

The previous prime is 91620511. The next prime is 91620559. The reversal of 91620553 is 35502619.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55175184 + 36445369 = 7428^2 + 6037^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91620553 is a prime.

It is not a weakly prime, because it can be changed into another prime (91620559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45810276 + 45810277.

It is an arithmetic number, because the mean of its divisors is an integer number (45810277).

Almost surely, 2^91620553 is an apocalyptic number.

It is an amenable number.

91620553 is a deficient number, since it is larger than the sum of its proper divisors (1).

91620553 is an equidigital number, since it uses as much as digits as its factorization.

91620553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 91620553 is about 9571.8625669198. The cubic root of 91620553 is about 450.8142508709.

The spelling of 91620553 in words is "ninety-one million, six hundred twenty thousand, five hundred fifty-three".