16464028492921 has 3 divisors (see below), whose sum is σ = 16464032550511. Its totient is φ = 16464024435332.

The previous prime is 16464028492867. The next prime is 16464028492973. The reversal of 16464028492921 is 12929482046461.

The square root of 16464028492921 is 4057589.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 12146193849321 + 4317834643600 = 3485139^2 + 2077940^2 .

It is not a de Polignac number, because 16464028492921 - 2⁹ = 16464028492409 is a prime.

It is a super-2 number, since 2×16464028492921² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16464028492421) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2028795 + ... + 6086383.

Almost surely, 2^{16464028492921} is an apocalyptic number.

16464028492921 is the 4057589-th square number.

16464028492921 is the 2028795-th centered octagonal number.

It is an amenable number.

16464028492921 is a deficient number, since it is larger than the sum of its proper divisors (4057590).

16464028492921 is an frugal number, since it uses more digits than its factorization.

16464028492921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8115178 (or 4057589 counting only the distinct ones).

The product of its (nonzero) digits is 11943936, while the sum is 58.

The spelling of 16464028492921 in words is "sixteen trillion, four hundred sixty-four billion, twenty-eight million, four hundred ninety-two thousand, nine hundred twenty-one".