149906681 has 2 divisors, whose sum is σ = 149906682. Its totient is φ = 149906680.

The previous prime is 149906677. The next prime is 149906683. The reversal of 149906681 is 186609941.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 139122025 + 10784656 = 11795^2 + 3284^2 .

It is a cyclic number.

It is not a de Polignac number, because 149906681 - 2² = 149906677 is a prime.

It is a super-2 number, since 2×149906681² = 44944026016871522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 149906683, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (149906683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74953340 + 74953341.

It is an arithmetic number, because the mean of its divisors is an integer number (74953341).

Almost surely, 2^149906681 is an apocalyptic number.

149906681 is the 6545-th centered heptagonal number.

It is an amenable number.

149906681 is a deficient number, since it is larger than the sum of its proper divisors (1).

149906681 is an equidigital number, since it uses as much as digits as its factorization.

149906681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 149906681 is about 12243.6383889757. The cubic root of 149906681 is about 531.2190770282.

The spelling of 149906681 in words is "one hundred forty-nine million, nine hundred six thousand, six hundred eighty-one".