137720646 has 48 divisors (see below), whose sum is σ = 342429984. Its totient is φ = 39186432.

The previous prime is 137720581. The next prime is 137720651. The reversal of 137720646 is 646027731.

137720646 is a `hidden beast` number, since 1 + 3 + 7 + 7 + 2 + 0 + 646 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 137720646.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30256 + ... + 34508.

It is an arithmetic number, because the mean of its divisors is an integer number (7133958).

Almost surely, 2^137720646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 137720646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171214992).

137720646 is an abundant number, since it is smaller than the sum of its proper divisors (204709338).

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

137720646 is a wasteful number, since it uses less digits than its factorization.

137720646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4525 (or 4522 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 36.

The square root of 137720646 is about 11735.4440052347. Note that the first 3 decimals coincide. The cubic root of 137720646 is about 516.4159931871.

The spelling of 137720646 in words is "one hundred thirty-seven million, seven hundred twenty thousand, six hundred forty-six".