137028781 has 4 divisors (see below), whose sum is σ = 137066112. Its totient is φ = 136991452.

The previous prime is 137028763. The next prime is 137028833. The reversal of 137028781 is 187820731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137028781 is a prime.

It is a super-2 number, since 2×137028781² = 37553773644691922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 137028781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137028701) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 12475 + ... + 20728.

It is an arithmetic number, because the mean of its divisors is an integer number (34266528).

Almost surely, 2^137028781 is an apocalyptic number.

It is an amenable number.

137028781 is a deficient number, since it is larger than the sum of its proper divisors (37331).

137028781 is an equidigital number, since it uses as much as digits as its factorization.

137028781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37330.

The product of its (nonzero) digits is 18816, while the sum is 37.

The square root of 137028781 is about 11705.9293095422. The cubic root of 137028781 is about 515.5497707743.

The spelling of 137028781 in words is "one hundred thirty-seven million, twenty-eight thousand, seven hundred eighty-one".