137521780 has 48 divisors (see below), whose sum is σ = 319402944. Its totient is φ = 49317120.

The previous prime is 137521763. The next prime is 137521781. The reversal of 137521780 is 87125731.

137521780 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137521781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11779 + ... + 20341.

It is an arithmetic number, because the mean of its divisors is an integer number (6654228).

Almost surely, 2^137521780 is an apocalyptic number.

137521780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 137521780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159701472).

137521780 is an abundant number, since it is smaller than the sum of its proper divisors (181881164).

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

137521780 is a wasteful number, since it uses less digits than its factorization.

137521780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8656 (or 8654 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 34.

The square root of 137521780 is about 11726.9680651053. The cubic root of 137521780 is about 516.1673084844.

The spelling of 137521780 in words is "one hundred thirty-seven million, five hundred twenty-one thousand, seven hundred eighty".