137651681 has 2 divisors, whose sum is σ = 137651682. Its totient is φ = 137651680.

The previous prime is 137651677. The next prime is 137651743. The reversal of 137651681 is 186156731.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133980625 + 3671056 = 11575^2 + 1916^2 .

It is a cyclic number.

It is not a de Polignac number, because 137651681 - 2² = 137651677 is a prime.

It is a super-2 number, since 2×137651681² = 37895970564251522, which contains 22 as substring.

It is equal to p_7787054 and since 137651681 and 7787054 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (137651611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68825840 + 68825841.

It is an arithmetic number, because the mean of its divisors is an integer number (68825841).

Almost surely, 2^137651681 is an apocalyptic number.

It is an amenable number.

137651681 is a deficient number, since it is larger than the sum of its proper divisors (1).

137651681 is an equidigital number, since it uses as much as digits as its factorization.

137651681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 38.

The square root of 137651681 is about 11732.5053164275. The cubic root of 137651681 is about 516.3297786254.

The spelling of 137651681 in words is "one hundred thirty-seven million, six hundred fifty-one thousand, six hundred eighty-one".