90897661 has 2 divisors, whose sum is σ = 90897662. Its totient is φ = 90897660.

The previous prime is 90897649. The next prime is 90897707. The reversal of 90897661 is 16679809.

90897661 = T₇₇₈₃ + T₇₇₈₄ + T₇₇₈₅.

It is an a-pointer prime, because the next prime (90897707) can be obtained adding 90897661 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63920025 + 26977636 = 7995^2 + 5194^2 .

It is an emirp because it is prime and its reverse (16679809) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90897661 - 2¹¹ = 90895613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90897601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45448830 + 45448831.

It is an arithmetic number, because the mean of its divisors is an integer number (45448831).

Almost surely, 2^90897661 is an apocalyptic number.

90897661 is the 7785-th centered triangular number.

It is an amenable number.

90897661 is a deficient number, since it is larger than the sum of its proper divisors (1).

90897661 is an equidigital number, since it uses as much as digits as its factorization.

90897661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 90897661 is about 9534.0264841252. The cubic root of 90897661 is about 449.6254677895.

The spelling of 90897661 in words is "ninety million, eight hundred ninety-seven thousand, six hundred sixty-one".