137126021 has 4 divisors (see below), whose sum is σ = 144343200. Its totient is φ = 129908844.

The previous prime is 137126009. The next prime is 137126039. The reversal of 137126021 is 120621731.

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, and also an emirpimes, since its reverse is a distinct semiprime: 120621731 = 97 ⋅1243523.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137126021 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 (137126081) 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, 3608561 + ... + 3608598.

It is an arithmetic number, because the mean of its divisors is an integer number (36085800).

Almost surely, 2^137126021 is an apocalyptic number.

It is an amenable number.

137126021 is a deficient number, since it is larger than the sum of its proper divisors (7217179).

137126021 is an equidigital number, since it uses as much as digits as its factorization.

137126021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7217178.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 137126021 is about 11710.0820236239. The cubic root of 137126021 is about 515.6716921341.

Adding to 137126021 its reverse (120621731), we get a palindrome (257747752).

The spelling of 137126021 in words is "one hundred thirty-seven million, one hundred twenty-six thousand, twenty-one".