16393129921 has 16 divisors (see below), whose sum is σ = 18892731904. Its totient is φ = 13933430784.

The previous prime is 16393129873. The next prime is 16393129981. The reversal of 16393129921 is 12992139361.

It is not a de Polignac number, because 16393129921 - 2²¹ = 16391032769 is a prime.

It is a super-3 number, since 3×16393129921³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16393129981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 403480 + ... + 442246.

It is an arithmetic number, because the mean of its divisors is an integer number (1180795744).

Almost surely, 2^16393129921 is an apocalyptic number.

It is an amenable number.

16393129921 is a deficient number, since it is larger than the sum of its proper divisors (2499601983).

16393129921 is a wasteful number, since it uses less digits than its factorization.

16393129921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39280.

The product of its digits is 157464, while the sum is 46.

The spelling of 16393129921 in words is "sixteen billion, three hundred ninety-three million, one hundred twenty-nine thousand, nine hundred twenty-one".