137781861 has 16 divisors (see below), whose sum is σ = 211058688. Its totient is φ = 78318000.

The previous prime is 137781857. The next prime is 137781911. The reversal of 137781861 is 168187731.

It is not a de Polignac number, because 137781861 - 2² = 137781857 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137781811) 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, 13165 + ... + 21186.

It is an arithmetic number, because the mean of its divisors is an integer number (13191168).

Almost surely, 2^137781861 is an apocalyptic number.

It is an amenable number.

137781861 is a deficient number, since it is larger than the sum of its proper divisors (73276827).

137781861 is a wasteful number, since it uses less digits than its factorization.

137781861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34552.

The product of its digits is 56448, while the sum is 42.

The square root of 137781861 is about 11738.0518400627. The cubic root of 137781861 is about 516.4924952061.

It can be divided in two parts, 1377 and 81861, that added together give a palindrome (83238).

The spelling of 137781861 in words is "one hundred thirty-seven million, seven hundred eighty-one thousand, eight hundred sixty-one".