90721672240 has 40 divisors (see below), whose sum is σ = 211673269008. Its totient is φ = 36160431360.

The previous prime is 90721672189. The next prime is 90721672277. The reversal of 90721672240 is 4227612709.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 90721672193 and 90721672202.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1980931 + ... + 2026210.

Almost surely, 2^90721672240 is an apocalyptic number.

It is an amenable number.

90721672240 is an abundant number, since it is smaller than the sum of its proper divisors (120951596768).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

90721672240 is a wasteful number, since it uses less digits than its factorization.

90721672240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4007437 (or 4007431 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 40.

The spelling of 90721672240 in words is "ninety billion, seven hundred twenty-one million, six hundred seventy-two thousand, two hundred forty".