72912137 has 4 divisors (see below), whose sum is σ = 72932100. Its totient is φ = 72892176.

The previous prime is 72912131. The next prime is 72912143. The reversal of 72912137 is 73121927.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73121927 = 53 ⋅1379659.

It is an interprime number because it is at equal distance from previous prime (72912131) and next prime (72912143).

It can be written as a sum of positive squares in 2 ways, for example, as 52940176 + 19971961 = 7276^2 + 4469^2 .

It is a cyclic number.

It is not a de Polignac number, because 72912137 - 2⁴ = 72912121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72912131) 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, 2762 + ... + 12387.

It is an arithmetic number, because the mean of its divisors is an integer number (18233025).

Almost surely, 2^72912137 is an apocalyptic number.

It is an amenable number.

72912137 is a deficient number, since it is larger than the sum of its proper divisors (19963).

72912137 is a wasteful number, since it uses less digits than its factorization.

72912137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19962.

The product of its digits is 5292, while the sum is 32.

The square root of 72912137 is about 8538.8604040586. The cubic root of 72912137 is about 417.7661768513.

The spelling of 72912137 in words is "seventy-two million, nine hundred twelve thousand, one hundred thirty-seven".