137106821 has 4 divisors (see below), whose sum is σ = 137796000. Its totient is φ = 136417644.

The previous prime is 137106817. The next prime is 137106839. The reversal of 137106821 is 128601731.

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 137106821 - 2² = 137106817 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 (137106811) 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, 344291 + ... + 344688.

It is an arithmetic number, because the mean of its divisors is an integer number (34449000).

Almost surely, 2^137106821 is an apocalyptic number.

It is an amenable number.

137106821 is a deficient number, since it is larger than the sum of its proper divisors (689179).

137106821 is an equidigital number, since it uses as much as digits as its factorization.

137106821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689178.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 137106821 is about 11709.2621885412. The cubic root of 137106821 is about 515.6476233771.

The spelling of 137106821 in words is "one hundred thirty-seven million, one hundred six thousand, eight hundred twenty-one".