153981971 has 32 divisors (see below), whose sum is σ = 193814208. Its totient is φ = 120176640.

The previous prime is 153981959. The next prime is 153981977. The reversal of 153981971 is 179189351.

It is a cyclic number.

It is not a de Polignac number, because 153981971 - 2¹⁸ = 153719827 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (153981977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 235481 + ... + 236133.

It is an arithmetic number, because the mean of its divisors is an integer number (6056694).

Almost surely, 2^153981971 is an apocalyptic number.

153981971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

153981971 is a deficient number, since it is larger than the sum of its proper divisors (39832237).

153981971 is a wasteful number, since it uses less digits than its factorization.

153981971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 791.

The product of its digits is 68040, while the sum is 44.

The square root of 153981971 is about 12408.9472156183. The cubic root of 153981971 is about 535.9899230952.

The spelling of 153981971 in words is "one hundred fifty-three million, nine hundred eighty-one thousand, nine hundred seventy-one".