90619681 has 4 divisors (see below), whose sum is σ = 90713412. Its totient is φ = 90525952.

The previous prime is 90619679. The next prime is 90619699. The reversal of 90619681 is 18691609.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18691609 = 97 ⋅192697.

It can be written as a sum of positive squares in 2 ways, for example, as 62157456 + 28462225 = 7884^2 + 5335^2 .

It is a cyclic number.

It is not a de Polignac number, because 90619681 - 2¹ = 90619679 is a prime.

It is a super-2 number, since 2×90619681² = 16423853169083522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90619601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45400 + ... + 47353.

It is an arithmetic number, because the mean of its divisors is an integer number (22678353).

Almost surely, 2^90619681 is an apocalyptic number.

It is an amenable number.

90619681 is a deficient number, since it is larger than the sum of its proper divisors (93731).

90619681 is an equidigital number, since it uses as much as digits as its factorization.

90619681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93730.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 90619681 is about 9519.4370106640. The cubic root of 90619681 is about 449.1666568835.

The spelling of 90619681 in words is "ninety million, six hundred nineteen thousand, six hundred eighty-one".