137916721 has 8 divisors (see below), whose sum is σ = 142804800. Its totient is φ = 133037520.

The previous prime is 137916697. The next prime is 137916731. The reversal of 137916721 is 127619731.

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 137916721 - 2⁷ = 137916593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137916731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53226 + ... + 55756.

It is an arithmetic number, because the mean of its divisors is an integer number (17850600).

Almost surely, 2^137916721 is an apocalyptic number.

It is an amenable number.

137916721 is a deficient number, since it is larger than the sum of its proper divisors (4888079).

137916721 is a wasteful number, since it uses less digits than its factorization.

137916721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4439.

The product of its digits is 15876, while the sum is 37.

The square root of 137916721 is about 11743.7949999138. The cubic root of 137916721 is about 516.6609534343.

The spelling of 137916721 in words is "one hundred thirty-seven million, nine hundred sixteen thousand, seven hundred twenty-one".