149997691 has 2 divisors, whose sum is σ = 149997692. Its totient is φ = 149997690.

The previous prime is 149997637. The next prime is 149997707. The reversal of 149997691 is 196799941.

149997691 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-149997691 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (149937691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74998845 + 74998846.

It is an arithmetic number, because the mean of its divisors is an integer number (74998846).

Almost surely, 2^149997691 is an apocalyptic number.

149997691 is a deficient number, since it is larger than the sum of its proper divisors (1).

149997691 is an equidigital number, since it uses as much as digits as its factorization.

149997691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1102248, while the sum is 55.

The square root of 149997691 is about 12247.3544490229. The cubic root of 149997691 is about 531.3265582677.

The spelling of 149997691 in words is "one hundred forty-nine million, nine hundred ninety-seven thousand, six hundred ninety-one".