72521901 has 6 divisors (see below), whose sum is σ = 104753870. Its totient is φ = 48347928.

The previous prime is 72521899. The next prime is 72521941. The reversal of 72521901 is 10912527.

It can be written as a sum of positive squares in only one way, i.e., 71419401 + 1102500 = 8451^2 + 1050^2 .

It is not a de Polignac number, because 72521901 - 2¹ = 72521899 is a prime.

It is a super-2 number, since 2×72521901² = 10518852249307602, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72521941) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4028986 + ... + 4029003.

Almost surely, 2^72521901 is an apocalyptic number.

It is an amenable number.

72521901 is a deficient number, since it is larger than the sum of its proper divisors (32231969).

72521901 is a wasteful number, since it uses less digits than its factorization.

72521901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8057995 (or 8057992 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 72521901 is about 8515.9791568557. The cubic root of 72521901 is about 417.0195287854.

The spelling of 72521901 in words is "seventy-two million, five hundred twenty-one thousand, nine hundred one".