137435621 has 4 divisors (see below), whose sum is σ = 137617932. Its totient is φ = 137253312.

The previous prime is 137435591. The next prime is 137435651. The reversal of 137435621 is 126534731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126534731 = 167 ⋅757693.

It is an interprime number because it is at equal distance from previous prime (137435591) and next prime (137435651).

It can be written as a sum of positive squares in 2 ways, for example, as 75498721 + 61936900 = 8689^2 + 7870^2 .

It is a cyclic number.

It is not a de Polignac number, because 137435621 - 2²⁶ = 70326757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137435651) 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, 90020 + ... + 91533.

It is an arithmetic number, because the mean of its divisors is an integer number (34404483).

Almost surely, 2^137435621 is an apocalyptic number.

It is an amenable number.

137435621 is a deficient number, since it is larger than the sum of its proper divisors (182311).

137435621 is an equidigital number, since it uses as much as digits as its factorization.

137435621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182310.

The product of its digits is 15120, while the sum is 32.

The square root of 137435621 is about 11723.2939483747. The cubic root of 137435621 is about 516.0594910176.

The spelling of 137435621 in words is "one hundred thirty-seven million, four hundred thirty-five thousand, six hundred twenty-one".