90181979 has 2 divisors, whose sum is σ = 90181980. Its totient is φ = 90181978.

The previous prime is 90181939. The next prime is 90182003. The reversal of 90181979 is 97918109.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 90181979 - 2¹² = 90177883 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (90181939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45090989 + 45090990.

It is an arithmetic number, because the mean of its divisors is an integer number (45090990).

Almost surely, 2^90181979 is an apocalyptic number.

90181979 is a deficient number, since it is larger than the sum of its proper divisors (1).

90181979 is an equidigital number, since it uses as much as digits as its factorization.

90181979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 90181979 is about 9496.4192725469. The cubic root of 90181979 is about 448.4423163270.

The spelling of 90181979 in words is "ninety million, one hundred eighty-one thousand, nine hundred seventy-nine".