137421997 has 2 divisors, whose sum is σ = 137421998. Its totient is φ = 137421996.

The previous prime is 137421967. The next prime is 137422007. The reversal of 137421997 is 799124731.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126472516 + 10949481 = 11246^2 + 3309^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137421997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (137421967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68710998 + 68710999.

It is an arithmetic number, because the mean of its divisors is an integer number (68710999).

Almost surely, 2^137421997 is an apocalyptic number.

It is an amenable number.

137421997 is a deficient number, since it is larger than the sum of its proper divisors (1).

137421997 is an equidigital number, since it uses as much as digits as its factorization.

137421997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 95256, while the sum is 43.

The square root of 137421997 is about 11722.7128686154. The cubic root of 137421997 is about 516.0424381197.

The spelling of 137421997 in words is "one hundred thirty-seven million, four hundred twenty-one thousand, nine hundred ninety-seven".