19979721058 has 16 divisors (see below), whose sum is σ = 32696454816. Its totient is φ = 9081034240.

The previous prime is 19979721007. The next prime is 19979721059. The reversal of 19979721058 is 85012797991.

It is a junction number, because it is equal to n+sod(n) for n = 19979720993 and 19979721011.

It is not an unprimeable number, because it can be changed into a prime (19979721059) 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, 411810 + ... + 457762.

It is an arithmetic number, because the mean of its divisors is an integer number (2043528426).

Almost surely, 2^19979721058 is an apocalyptic number.

19979721058 is a deficient number, since it is larger than the sum of its proper divisors (12716733758).

19979721058 is a wasteful number, since it uses less digits than its factorization.

19979721058 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65729.

The product of its (nonzero) digits is 2857680, while the sum is 58.

The spelling of 19979721058 in words is "nineteen billion, nine hundred seventy-nine million, seven hundred twenty-one thousand, fifty-eight".