137744221 has 2 divisors, whose sum is σ = 137744222. Its totient is φ = 137744220.

The previous prime is 137744219. The next prime is 137744231. The reversal of 137744221 is 122447731.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137592900 + 151321 = 11730^2 + 389^2 .

It is a cyclic number.

It is not a de Polignac number, because 137744221 - 2¹ = 137744219 is a prime.

Together with 137744219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (137744231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68872110 + 68872111.

It is an arithmetic number, because the mean of its divisors is an integer number (68872111).

Almost surely, 2^137744221 is an apocalyptic number.

It is an amenable number.

137744221 is a deficient number, since it is larger than the sum of its proper divisors (1).

137744221 is an equidigital number, since it uses as much as digits as its factorization.

137744221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 31.

The square root of 137744221 is about 11736.4483980461. The cubic root of 137744221 is about 516.4454581773.

The spelling of 137744221 in words is "one hundred thirty-seven million, seven hundred forty-four thousand, two hundred twenty-one".