72912811 has 4 divisors (see below), whose sum is σ = 73939824. Its totient is φ = 71885800.

The previous prime is 72912803. The next prime is 72912877. The reversal of 72912811 is 11821927.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11821927 = 13 ⋅909379.

It is a cyclic number.

It is not a de Polignac number, because 72912811 - 2³ = 72912803 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72912211) 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, 513400 + ... + 513541.

It is an arithmetic number, because the mean of its divisors is an integer number (18484956).

Almost surely, 2^72912811 is an apocalyptic number.

72912811 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

72912811 is a deficient number, since it is larger than the sum of its proper divisors (1027013).

72912811 is a wasteful number, since it uses less digits than its factorization.

72912811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027012.

The product of its digits is 2016, while the sum is 31.

The square root of 72912811 is about 8538.8998705922. The cubic root of 72912811 is about 417.7674641246.

The spelling of 72912811 in words is "seventy-two million, nine hundred twelve thousand, eight hundred eleven".