137721390 has 16 divisors (see below), whose sum is σ = 330531408. Its totient is φ = 36725696.

The previous prime is 137721379. The next prime is 137721413. The reversal of 137721390 is 93127731.

It is a happy number.

137721390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2295327 + ... + 2295386.

It is an arithmetic number, because the mean of its divisors is an integer number (20658213).

Almost surely, 2^137721390 is an apocalyptic number.

137721390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

137721390 is an abundant number, since it is smaller than the sum of its proper divisors (192810018).

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

137721390 is a wasteful number, since it uses less digits than its factorization.

137721390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4590723.

The product of its (nonzero) digits is 7938, while the sum is 33.

The square root of 137721390 is about 11735.4757040352. The cubic root of 137721390 is about 516.4169231199.

The spelling of 137721390 in words is "one hundred thirty-seven million, seven hundred twenty-one thousand, three hundred ninety".