7257137321 has 4 divisors (see below), whose sum is σ = 8293871232. Its totient is φ = 6220403412.

The previous prime is 7257137311. The next prime is 7257137333. The reversal of 7257137321 is 1237317527.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7257137321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7257137311) 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, 518366945 + ... + 518366958.

It is an arithmetic number, because the mean of its divisors is an integer number (2073467808).

Almost surely, 2^7257137321 is an apocalyptic number.

It is an amenable number.

7257137321 is a deficient number, since it is larger than the sum of its proper divisors (1036733911).

7257137321 is a wasteful number, since it uses less digits than its factorization.

7257137321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036733910.

The product of its digits is 61740, while the sum is 38.

The square root of 7257137321 is about 85188.8333116495. The cubic root of 7257137321 is about 1936.0732313022.

The spelling of 7257137321 in words is "seven billion, two hundred fifty-seven million, one hundred thirty-seven thousand, three hundred twenty-one".