137721755 has 4 divisors (see below), whose sum is σ = 165266112. Its totient is φ = 110177400.

The previous prime is 137721751. The next prime is 137721799. The reversal of 137721755 is 557127731.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 137721755 - 2² = 137721751 is a prime.

It is a super-3 number, since 3×137721755³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137721751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13772171 + ... + 13772180.

It is an arithmetic number, because the mean of its divisors is an integer number (41316528).

Almost surely, 2^137721755 is an apocalyptic number.

137721755 is a deficient number, since it is larger than the sum of its proper divisors (27544357).

137721755 is an equidigital number, since it uses as much as digits as its factorization.

137721755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27544356.

The product of its digits is 51450, while the sum is 38.

The square root of 137721755 is about 11735.4912551627. The cubic root of 137721755 is about 516.4173793356.

It can be divided in two parts, 1377 and 21755, that added together give a palindrome (23132).

The spelling of 137721755 in words is "one hundred thirty-seven million, seven hundred twenty-one thousand, seven hundred fifty-five".