149664681 has 6 divisors (see below), whose sum is σ = 216182330. Its totient is φ = 99776448.

The previous prime is 149664677. The next prime is 149664701. The reversal of 149664681 is 186466941.

It can be written as a sum of positive squares in only one way, i.e., 75429225 + 74235456 = 8685^2 + 8616^2 .

It is not a de Polignac number, because 149664681 - 2² = 149664677 is a prime.

It is a super-4 number, since 4×149664681⁴ (a number of 34 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (149664601) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8314696 + ... + 8314713.

Almost surely, 2^149664681 is an apocalyptic number.

It is an amenable number.

149664681 is a deficient number, since it is larger than the sum of its proper divisors (66517649).

149664681 is a wasteful number, since it uses less digits than its factorization.

149664681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16629415 (or 16629412 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 149664681 is about 12233.7517140083. The cubic root of 149664681 is about 530.9330674144.

The spelling of 149664681 in words is "one hundred forty-nine million, six hundred sixty-four thousand, six hundred eighty-one".