137504721 has 8 divisors (see below), whose sum is σ = 194124384. Its totient is φ = 86277440.

The previous prime is 137504713. The next prime is 137504723. The reversal of 137504721 is 127405731.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 137504721 - 2³ = 137504713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (137504723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1348035 + ... + 1348136.

It is an arithmetic number, because the mean of its divisors is an integer number (24265548).

Almost surely, 2^137504721 is an apocalyptic number.

It is an amenable number.

137504721 is a deficient number, since it is larger than the sum of its proper divisors (56619663).

137504721 is a wasteful number, since it uses less digits than its factorization.

137504721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2696191.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 137504721 is about 11726.2407019471. The cubic root of 137504721 is about 516.1459648053.

The spelling of 137504721 in words is "one hundred thirty-seven million, five hundred four thousand, seven hundred twenty-one".