72738121 has 24 divisors (see below), whose sum is σ = 83464704. Its totient is φ = 63191040.

The previous prime is 72738103. The next prime is 72738131. The reversal of 72738121 is 12183727.

It is not a de Polignac number, because 72738121 - 2⁷ = 72737993 is a prime.

It is a super-2 number, since 2×72738121² = 10581668493221282, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72738131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 205881 + ... + 206233.

It is an arithmetic number, because the mean of its divisors is an integer number (3477696).

Almost surely, 2^72738121 is an apocalyptic number.

It is an amenable number.

72738121 is a deficient number, since it is larger than the sum of its proper divisors (10726583).

72738121 is a wasteful number, since it uses less digits than its factorization.

72738121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 424 counting only the distinct ones).

The product of its digits is 4704, while the sum is 31.

The square root of 72738121 is about 8528.6646668749. The cubic root of 72738121 is about 417.4335577392.

The spelling of 72738121 in words is "seventy-two million, seven hundred thirty-eight thousand, one hundred twenty-one".