137215728 has 160 divisors (see below), whose sum is σ = 433097280. Its totient is φ = 41333760.

The previous prime is 137215699. The next prime is 137215763. The reversal of 137215728 is 827512731.

137215728 is a `hidden beast` number, since 13 + 72 + 1 + 572 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 137215692 and 137215701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 297418 + ... + 297878.

It is an arithmetic number, because the mean of its divisors is an integer number (2706858).

Almost surely, 2^137215728 is an apocalyptic number.

137215728 is a gapful number since it is divisible by the number (18) 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 137215728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216548640).

137215728 is an abundant number, since it is smaller than the sum of its proper divisors (295881552).

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

137215728 is a wasteful number, since it uses less digits than its factorization.

137215728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544 (or 532 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 137215728 is about 11713.9117292218. The cubic root of 137215728 is about 515.7841173721.

The spelling of 137215728 in words is "one hundred thirty-seven million, two hundred fifteen thousand, seven hundred twenty-eight".