90172939 has 2 divisors, whose sum is σ = 90172940. Its totient is φ = 90172938.

The previous prime is 90172937. The next prime is 90172967. The reversal of 90172939 is 93927109.

It is a weak prime.

It is an emirp because it is prime and its reverse (93927109) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90172939 - 2¹ = 90172937 is a prime.

Together with 90172937, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (90172937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45086469 + 45086470.

It is an arithmetic number, because the mean of its divisors is an integer number (45086470).

Almost surely, 2^90172939 is an apocalyptic number.

90172939 is a deficient number, since it is larger than the sum of its proper divisors (1).

90172939 is an equidigital number, since it uses as much as digits as its factorization.

90172939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 90172939 is about 9495.9432917431. The cubic root of 90172939 is about 448.4273316111.

The spelling of 90172939 in words is "ninety million, one hundred seventy-two thousand, nine hundred thirty-nine".