163972981 has 8 divisors (see below), whose sum is σ = 173392128. Its totient is φ = 154812000.

The previous prime is 163972979. The next prime is 163972987. The reversal of 163972981 is 189279361.

It is a happy number.

163972981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 163972981 - 2¹ = 163972979 is a prime.

It is a super-2 number, since 2×163972981² = 53774276996052722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163972987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63235 + ... + 65776.

It is an arithmetic number, because the mean of its divisors is an integer number (21674016).

Almost surely, 2^163972981 is an apocalyptic number.

It is an amenable number.

163972981 is a deficient number, since it is larger than the sum of its proper divisors (9419147).

163972981 is a wasteful number, since it uses less digits than its factorization.

163972981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129083.

The product of its digits is 163296, while the sum is 46.

The square root of 163972981 is about 12805.1935166947. The cubic root of 163972981 is about 547.3403060729.

The spelling of 163972981 in words is "one hundred sixty-three million, nine hundred seventy-two thousand, nine hundred eighty-one".