137000021 has 4 divisors (see below), whose sum is σ = 140186112. Its totient is φ = 133813932.

The previous prime is 137000009. The next prime is 137000027. The reversal of 137000021 is 120000731.

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 not a de Polignac number, because 137000021 - 2¹⁰ = 136998997 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 (137000027) 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, 1592981 + ... + 1593066.

It is an arithmetic number, because the mean of its divisors is an integer number (35046528).

Almost surely, 2^137000021 is an apocalyptic number.

It is an amenable number.

137000021 is a deficient number, since it is larger than the sum of its proper divisors (3186091).

137000021 is an equidigital number, since it uses as much as digits as its factorization.

137000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3186090.

The product of its (nonzero) digits is 42, while the sum is 14.

The square root of 137000021 is about 11704.7008077951. The cubic root of 137000021 is about 515.5136998877.

Adding to 137000021 its reverse (120000731), we get a palindrome (257000752).

The spelling of 137000021 in words is "one hundred thirty-seven million, twenty-one", and thus it is an aban number.