163490026921 has 27 divisors (see below), whose sum is σ = 186955740261. Its totient is φ = 142883698464.

The previous prime is 163490026891. The next prime is 163490026933. The reversal of 163490026921 is 129620094361.

The square root of 163490026921 is 404339.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 115913692521 + 47576334400 = 340461^2 + 218120^2 .

It is not a de Polignac number, because 163490026921 - 2⁷ = 163490026793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163490026981) 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 in 26 ways as a sum of consecutive naturals, for example, 99870915 + ... + 99872551.

Almost surely, 2^163490026921 is an apocalyptic number.

163490026921 is the 404339-th square number.

163490026921 is the 202170-th centered octagonal number.

It is an amenable number.

163490026921 is a deficient number, since it is larger than the sum of its proper divisors (23465713340).

163490026921 is an frugal number, since it uses more digits than its factorization.

163490026921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3338 (or 1669 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 163490026921 in words is "one hundred sixty-three billion, four hundred ninety million, twenty-six thousand, nine hundred twenty-one".