91210139 has 2 divisors, whose sum is σ = 91210140. Its totient is φ = 91210138.

The previous prime is 91210123. The next prime is 91210177. The reversal of 91210139 is 93101219.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91210139 - 2⁴ = 91210123 is a prime.

It is a Chen prime.

It is a plaindrome in base 12.

It is not a weakly prime, because it can be changed into another prime (91210039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45605069 + 45605070.

It is an arithmetic number, because the mean of its divisors is an integer number (45605070).

Almost surely, 2^91210139 is an apocalyptic number.

91210139 is a deficient number, since it is larger than the sum of its proper divisors (1).

91210139 is an equidigital number, since it uses as much as digits as its factorization.

91210139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 91210139 is about 9550.3999392696. The cubic root of 91210139 is about 450.1401028779.

The spelling of 91210139 in words is "ninety-one million, two hundred ten thousand, one hundred thirty-nine".