91913639 has 2 divisors, whose sum is σ = 91913640. Its totient is φ = 91913638.

The previous prime is 91913603. The next prime is 91913671. The reversal of 91913639 is 93631919.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91913639 - 2¹⁶ = 91848103 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 91913596 and 91913605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91913039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45956819 + 45956820.

It is an arithmetic number, because the mean of its divisors is an integer number (45956820).

Almost surely, 2^91913639 is an apocalyptic number.

91913639 is a deficient number, since it is larger than the sum of its proper divisors (1).

91913639 is an equidigital number, since it uses as much as digits as its factorization.

91913639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39366, while the sum is 41.

The square root of 91913639 is about 9587.1601113156. The cubic root of 91913639 is about 451.2944440997.

The spelling of 91913639 in words is "ninety-one million, nine hundred thirteen thousand, six hundred thirty-nine".