137521720 has 32 divisors (see below), whose sum is σ = 353628000. Its totient is φ = 47150208.

The previous prime is 137521691. The next prime is 137521733. The reversal of 137521720 is 27125731.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

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, 245295 + ... + 245854.

It is an arithmetic number, because the mean of its divisors is an integer number (11050875).

Almost surely, 2^137521720 is an apocalyptic number.

137521720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

137521720 is an abundant number, since it is smaller than the sum of its proper divisors (216106280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

137521720 is a wasteful number, since it uses less digits than its factorization.

137521720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491167 (or 491163 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 137521720 is about 11726.9655068990. The cubic root of 137521720 is about 516.1672334174.

The spelling of 137521720 in words is "one hundred thirty-seven million, five hundred twenty-one thousand, seven hundred twenty".