72157823 has 2 divisors, whose sum is σ = 72157824. Its totient is φ = 72157822.

The previous prime is 72157817. The next prime is 72157847. The reversal of 72157823 is 32875127.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72157823 - 2⁸ = 72157567 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72157853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36078911 + 36078912.

It is an arithmetic number, because the mean of its divisors is an integer number (36078912).

Almost surely, 2^72157823 is an apocalyptic number.

72157823 is a deficient number, since it is larger than the sum of its proper divisors (1).

72157823 is an equidigital number, since it uses as much as digits as its factorization.

72157823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23520, while the sum is 35.

The square root of 72157823 is about 8494.5760930137. The cubic root of 72157823 is about 416.3205104395.

The spelling of 72157823 in words is "seventy-two million, one hundred fifty-seven thousand, eight hundred twenty-three".