137721690 has 96 divisors (see below), whose sum is σ = 385894080. Its totient is φ = 33965568.

The previous prime is 137721559. The next prime is 137721691. The reversal of 137721690 is 96127731.

It is a happy number.

137721690 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×137721690² = 37934527792912200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (137721691) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 72594 + ... + 74466.

It is an arithmetic number, because the mean of its divisors is an integer number (4019730).

Almost surely, 2^137721690 is an apocalyptic number.

137721690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 137721690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192947040).

137721690 is an abundant number, since it is smaller than the sum of its proper divisors (248172390).

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

137721690 is a wasteful number, since it uses less digits than its factorization.

137721690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1948 (or 1945 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 36.

The square root of 137721690 is about 11735.4884857853. The cubic root of 137721690 is about 516.4172980918.

The spelling of 137721690 in words is "one hundred thirty-seven million, seven hundred twenty-one thousand, six hundred ninety".