90931015217657 has 2 divisors, whose sum is σ = 90931015217658. Its totient is φ = 90931015217656.

The previous prime is 90931015217599. The next prime is 90931015217729. The reversal of 90931015217657 is 75671251013909.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90389818110736 + 541197106921 = 9507356^2 + 735661^2 .

It is an emirp because it is prime and its reverse (75671251013909) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90931015217657 - 2¹² = 90931015213561 is a prime.

It is a super-2 number, since 2×90931015217657² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (90931035217657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45465507608828 + 45465507608829.

It is an arithmetic number, because the mean of its divisors is an integer number (45465507608829).

Almost surely, 2^{90931015217657} is an apocalyptic number.

It is an amenable number.

90931015217657 is a deficient number, since it is larger than the sum of its proper divisors (1).

90931015217657 is an equidigital number, since it uses as much as digits as its factorization.

90931015217657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3572100, while the sum is 56.

The spelling of 90931015217657 in words is "ninety trillion, nine hundred thirty-one billion, fifteen million, two hundred seventeen thousand, six hundred fifty-seven".