72381381 has 4 divisors (see below), whose sum is σ = 96508512. Its totient is φ = 48254252.

The previous prime is 72381371. The next prime is 72381383. The reversal of 72381381 is 18318327.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72381381 - 2¹⁵ = 72348613 is a prime.

It is a super-2 number, since 2×72381381² = 10478128630934322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72381383) 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, 12063561 + ... + 12063566.

It is an arithmetic number, because the mean of its divisors is an integer number (24127128).

Almost surely, 2^72381381 is an apocalyptic number.

It is an amenable number.

72381381 is a deficient number, since it is larger than the sum of its proper divisors (24127131).

72381381 is a wasteful number, since it uses less digits than its factorization.

72381381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24127130.

The product of its digits is 8064, while the sum is 33.

The square root of 72381381 is about 8507.7247839831. The cubic root of 72381381 is about 416.7500126249.

The spelling of 72381381 in words is "seventy-two million, three hundred eighty-one thousand, three hundred eighty-one".