16721720338870 has 16 divisors (see below), whose sum is σ = 30106852180128. Its totient is φ = 6686964675520.

The previous prime is 16721720338849. The next prime is 16721720338871. The reversal of 16721720338870 is 7883302712761.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16721720338871) 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, 215391754 + ... + 215469373.

It is an arithmetic number, because the mean of its divisors is an integer number (1881678261258).

Almost surely, 2^{16721720338870} is an apocalyptic number.

16721720338870 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16721720338870 is a deficient number, since it is larger than the sum of its proper divisors (13385131841258).

16721720338870 is a wasteful number, since it uses less digits than its factorization.

16721720338870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430865015.

The product of its (nonzero) digits is 4741632, while the sum is 55.

The spelling of 16721720338870 in words is "sixteen trillion, seven hundred twenty-one billion, seven hundred twenty million, three hundred thirty-eight thousand, eight hundred seventy".