137732721 has 16 divisors (see below), whose sum is σ = 216649728. Its totient is φ = 76165200.

The previous prime is 137732681. The next prime is 137732723. The reversal of 137732721 is 127237731.

It is not a de Polignac number, because 137732721 - 2¹⁵ = 137699953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (137732723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105135 + ... + 106436.

It is an arithmetic number, because the mean of its divisors is an integer number (13540608).

Almost surely, 2^137732721 is an apocalyptic number.

It is an amenable number.

137732721 is a deficient number, since it is larger than the sum of its proper divisors (78917007).

137732721 is a wasteful number, since it uses less digits than its factorization.

137732721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211612.

The product of its digits is 12348, while the sum is 33.

The square root of 137732721 is about 11735.9584610717. The cubic root of 137732721 is about 516.4310854314.

The spelling of 137732721 in words is "one hundred thirty-seven million, seven hundred thirty-two thousand, seven hundred twenty-one".