149681681 has 2 divisors, whose sum is σ = 149681682. Its totient is φ = 149681680.

The previous prime is 149681657. The next prime is 149681689. The reversal of 149681681 is 186186941.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88529281 + 61152400 = 9409^2 + 7820^2 .

It is a cyclic number.

It is not a de Polignac number, because 149681681 - 2²⁶ = 82572817 is a prime.

It is a super-2 number, since 2×149681681² = 44809211253971522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (149681689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74840840 + 74840841.

It is an arithmetic number, because the mean of its divisors is an integer number (74840841).

Almost surely, 2^149681681 is an apocalyptic number.

It is an amenable number.

149681681 is a deficient number, since it is larger than the sum of its proper divisors (1).

149681681 is an equidigital number, since it uses as much as digits as its factorization.

149681681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 44.

The square root of 149681681 is about 12234.4464934054. The cubic root of 149681681 is about 530.9531690629.

The spelling of 149681681 in words is "one hundred forty-nine million, six hundred eighty-one thousand, six hundred eighty-one".