72157151421 has 12 divisors (see below), whose sum is σ = 104486919420. Its totient is φ = 47984803200.

The previous prime is 72157151401. The next prime is 72157151461. The reversal of 72157151421 is 12415175127.

It is a happy number.

72157151421 is a `hidden beast` number, since 7 + 215 + 7 + 15 + 1 + 421 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 71749515321 + 407636100 = 267861^2 + 20190^2 .

It is not a de Polignac number, because 72157151421 - 2¹⁷ = 72157020349 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72157151401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9993226 + ... + 10000443.

It is an arithmetic number, because the mean of its divisors is an integer number (8707243285).

Almost surely, 2^72157151421 is an apocalyptic number.

It is an amenable number.

72157151421 is a deficient number, since it is larger than the sum of its proper divisors (32329767999).

72157151421 is a wasteful number, since it uses less digits than its factorization.

72157151421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19994076 (or 19994073 counting only the distinct ones).

The product of its digits is 19600, while the sum is 36.

The spelling of 72157151421 in words is "seventy-two billion, one hundred fifty-seven million, one hundred fifty-one thousand, four hundred twenty-one".