72157105 has 4 divisors (see below), whose sum is σ = 86588532. Its totient is φ = 57725680.

The previous prime is 72157097. The next prime is 72157109. The reversal of 72157105 is 50175127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50175127 = 191 ⋅262697.

It can be written as a sum of positive squares in 2 ways, for example, as 19289664 + 52867441 = 4392^2 + 7271^2 .

It is not a de Polignac number, because 72157105 - 2³ = 72157097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72157109) 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, 7215706 + ... + 7215715.

It is an arithmetic number, because the mean of its divisors is an integer number (21647133).

Almost surely, 2^72157105 is an apocalyptic number.

It is an amenable number.

72157105 is a deficient number, since it is larger than the sum of its proper divisors (14431427).

72157105 is a wasteful number, since it uses less digits than its factorization.

72157105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14431426.

The product of its (nonzero) digits is 2450, while the sum is 28.

The square root of 72157105 is about 8494.5338306466. The cubic root of 72157105 is about 416.3191295815.

The spelling of 72157105 in words is "seventy-two million, one hundred fifty-seven thousand, one hundred five".