537387721 has 12 divisors (see below), whose sum is σ = 585837900. Its totient is φ = 492697920.

The previous prime is 537387701. The next prime is 537387751. The reversal of 537387721 is 127783735.

It can be written as a sum of positive squares in 6 ways, for example, as 32936121 + 504451600 = 5739^2 + 22460^2 .

It is not a de Polignac number, because 537387721 - 2⁵ = 537387689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (537387701) 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, 14511 + ... + 35851.

It is an arithmetic number, because the mean of its divisors is an integer number (48819825).

Almost surely, 2^537387721 is an apocalyptic number.

It is an amenable number.

537387721 is a deficient number, since it is larger than the sum of its proper divisors (48450179).

537387721 is a wasteful number, since it uses less digits than its factorization.

537387721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21516 (or 21503 counting only the distinct ones).

The product of its digits is 246960, while the sum is 43.

The square root of 537387721 is about 23181.6246410816. The cubic root of 537387721 is about 813.0100477500.

The spelling of 537387721 in words is "five hundred thirty-seven million, three hundred eighty-seven thousand, seven hundred twenty-one".