149640581 has 2 divisors, whose sum is σ = 149640582. Its totient is φ = 149640580.

The previous prime is 149640577. The next prime is 149640587. The reversal of 149640581 is 185046941.

149640581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148620481 + 1020100 = 12191^2 + 1010^2 .

It is a cyclic number.

It is not a de Polignac number, because 149640581 - 2² = 149640577 is a prime.

It is a super-2 number, since 2×149640581² = 44784606964035122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (149640587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74820290 + 74820291.

It is an arithmetic number, because the mean of its divisors is an integer number (74820291).

Almost surely, 2^149640581 is an apocalyptic number.

It is an amenable number.

149640581 is a deficient number, since it is larger than the sum of its proper divisors (1).

149640581 is an equidigital number, since it uses as much as digits as its factorization.

149640581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 149640581 is about 12232.7666944155. The cubic root of 149640581 is about 530.9045677628.

The spelling of 149640581 in words is "one hundred forty-nine million, six hundred forty thousand, five hundred eighty-one".