90547429921 has 27 divisors (see below), whose sum is σ = 99645312249. Its totient is φ = 82242587232.

The previous prime is 90547429913. The next prime is 90547429939. The reversal of 90547429921 is 12992474509.

The square root of 90547429921 is 300911.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 2314668321 + 88232761600 = 48111^2 + 297040^2 .

It is not a de Polignac number, because 90547429921 - 2³ = 90547429913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90547429981) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 309035451 + ... + 309035743.

Almost surely, 2^90547429921 is an apocalyptic number.

90547429921 is the 300911-st square number.

90547429921 is the 150456-th centered octagonal number.

It is an amenable number.

90547429921 is a deficient number, since it is larger than the sum of its proper divisors (9097882328).

90547429921 is an frugal number, since it uses more digits than its factorization.

90547429921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770 (or 385 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 90547429921 in words is "ninety billion, five hundred forty-seven million, four hundred twenty-nine thousand, nine hundred twenty-one".