90619561 has 2 divisors, whose sum is σ = 90619562. Its totient is φ = 90619560.

The previous prime is 90619547. The next prime is 90619567. The reversal of 90619561 is 16591609.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66912400 + 23707161 = 8180^2 + 4869^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90619561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90619561.

It is not a weakly prime, because it can be changed into another prime (90619567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45309780 + 45309781.

It is an arithmetic number, because the mean of its divisors is an integer number (45309781).

Almost surely, 2^90619561 is an apocalyptic number.

It is an amenable number.

90619561 is a deficient number, since it is larger than the sum of its proper divisors (1).

90619561 is an equidigital number, since it uses as much as digits as its factorization.

90619561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 90619561 is about 9519.4307077682. The cubic root of 90619561 is about 449.1664586189.

The spelling of 90619561 in words is "ninety million, six hundred nineteen thousand, five hundred sixty-one".