2572136821 has 4 divisors (see below), whose sum is σ = 2572397100. Its totient is φ = 2571876544.

The previous prime is 2572136803. The next prime is 2572136857. The reversal of 2572136821 is 1286312752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1524902500 + 1047234321 = 39050^2 + 32361^2 .

It is a cyclic number.

It is not a de Polignac number, because 2572136821 - 2²¹ = 2570039669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2572136221) 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, 114706 + ... + 135283.

It is an arithmetic number, because the mean of its divisors is an integer number (643099275).

Almost surely, 2^2572136821 is an apocalyptic number.

It is an amenable number.

2572136821 is a deficient number, since it is larger than the sum of its proper divisors (260279).

2572136821 is a wasteful number, since it uses less digits than its factorization.

2572136821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260278.

The product of its digits is 40320, while the sum is 37.

The square root of 2572136821 is about 50716.2382378662. The cubic root of 2572136821 is about 1370.1391907525.

The spelling of 2572136821 in words is "two billion, five hundred seventy-two million, one hundred thirty-six thousand, eight hundred twenty-one".