137415821 has 4 divisors (see below), whose sum is σ = 137443644. Its totient is φ = 137388000.

The previous prime is 137415793. The next prime is 137415841. The reversal of 137415821 is 128514731.

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

It can be written as a sum of positive squares in 2 ways, for example, as 33477796 + 103938025 = 5786^2 + 10195^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137415821 is a prime.

It is a super-2 number, since 2×137415821² = 37766215722208082, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137415841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4280 + ... + 17121.

It is an arithmetic number, because the mean of its divisors is an integer number (34360911).

It is a Poulet number, since it divides 2^137415820-1.

Almost surely, 2^137415821 is an apocalyptic number.

It is an amenable number.

137415821 is a deficient number, since it is larger than the sum of its proper divisors (27823).

137415821 is an equidigital number, since it uses as much as digits as its factorization.

137415821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27822.

The product of its digits is 6720, while the sum is 32.

The square root of 137415821 is about 11722.4494454018. The cubic root of 137415821 is about 516.0347073684.

The spelling of 137415821 in words is "one hundred thirty-seven million, four hundred fifteen thousand, eight hundred twenty-one".