137951221 has 2 divisors, whose sum is σ = 137951222. Its totient is φ = 137951220.

The previous prime is 137951179. The next prime is 137951227. The reversal of 137951221 is 122159731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95844100 + 42107121 = 9790^2 + 6489^2 .

It is an emirp because it is prime and its reverse (122159731) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 137951221 - 2²³ = 129562613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (137951227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68975610 + 68975611.

It is an arithmetic number, because the mean of its divisors is an integer number (68975611).

Almost surely, 2^137951221 is an apocalyptic number.

It is an amenable number.

137951221 is a deficient number, since it is larger than the sum of its proper divisors (1).

137951221 is an equidigital number, since it uses as much as digits as its factorization.

137951221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 31.

The square root of 137951221 is about 11745.2637688559. The cubic root of 137951221 is about 516.7040309202.

The spelling of 137951221 in words is "one hundred thirty-seven million, nine hundred fifty-one thousand, two hundred twenty-one".