38972721 has 8 divisors (see below), whose sum is σ = 55020384. Its totient is φ = 24453440.

The previous prime is 38972719. The next prime is 38972753. The reversal of 38972721 is 12727983.

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 38972721 - 2¹ = 38972719 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 38972721.

It is not an unprimeable number, because it can be changed into a prime (38972711) 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, 382035 + ... + 382136.

It is an arithmetic number, because the mean of its divisors is an integer number (6877548).

Almost surely, 2^38972721 is an apocalyptic number.

It is an amenable number.

38972721 is a deficient number, since it is larger than the sum of its proper divisors (16047663).

38972721 is a wasteful number, since it uses less digits than its factorization.

38972721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764191.

The product of its digits is 42336, while the sum is 39.

The square root of 38972721 is about 6242.8135483931. The cubic root of 38972721 is about 339.0420584603.

It can be divided in two parts, 38972 and 721, that added together give a palindrome (39693).

The spelling of 38972721 in words is "thirty-eight million, nine hundred seventy-two thousand, seven hundred twenty-one".