72251981 has 8 divisors (see below), whose sum is σ = 72797760. Its totient is φ = 71708832.

The previous prime is 72251957. The next prime is 72251983. The reversal of 72251981 is 18915227.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72251981 - 2¹⁸ = 71989837 is a prime.

It is a super-2 number, since 2×72251981² = 10440697516848722, 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 (72251983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112046 + ... + 112688.

It is an arithmetic number, because the mean of its divisors is an integer number (9099720).

Almost surely, 2^72251981 is an apocalyptic number.

It is an amenable number.

72251981 is a deficient number, since it is larger than the sum of its proper divisors (545779).

72251981 is a wasteful number, since it uses less digits than its factorization.

72251981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1315.

The product of its digits is 10080, while the sum is 35.

The square root of 72251981 is about 8500.1165286130. The cubic root of 72251981 is about 416.5015158469.

The spelling of 72251981 in words is "seventy-two million, two hundred fifty-one thousand, nine hundred eighty-one".