90720139 has 2 divisors, whose sum is σ = 90720140. Its totient is φ = 90720138.

The previous prime is 90720137. The next prime is 90720151. The reversal of 90720139 is 93102709.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 90720139 - 2¹ = 90720137 is a prime.

Together with 90720137, it forms a pair of twin primes.

It is equal to p_5256382 and since 90720139 and 5256382 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90720139.

It is not a weakly prime, because it can be changed into another prime (90720137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45360069 + 45360070.

It is an arithmetic number, because the mean of its divisors is an integer number (45360070).

Almost surely, 2^90720139 is an apocalyptic number.

90720139 is a deficient number, since it is larger than the sum of its proper divisors (1).

90720139 is an equidigital number, since it uses as much as digits as its factorization.

90720139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 90720139 is about 9524.7120166439. The cubic root of 90720139 is about 449.3325727200.

The spelling of 90720139 in words is "ninety million, seven hundred twenty thousand, one hundred thirty-nine".