149891856021 has 20 divisors (see below), whose sum is σ = 223928254572. Its totient is φ = 99920884608.

The previous prime is 149891855989. The next prime is 149891856073. The reversal of 149891856021 is 120658198941.

149891856021 is a `hidden beast` number, since 1 + 49 + 8 + 9 + 18 + 560 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 135464483025 + 14427372996 = 368055^2 + 120114^2 .

It is not a de Polignac number, because 149891856021 - 2⁵ = 149891855989 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (149891852021) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1261255 + ... + 1374971.

Almost surely, 2^149891856021 is an apocalyptic number.

It is an amenable number.

149891856021 is a deficient number, since it is larger than the sum of its proper divisors (74036398551).

149891856021 is a wasteful number, since it uses less digits than its factorization.

149891856021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130002 (or 129993 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 54.

The spelling of 149891856021 in words is "one hundred forty-nine billion, eight hundred ninety-one million, eight hundred fifty-six thousand, twenty-one".