19946190021 has 16 divisors (see below), whose sum is σ = 26926468800. Its totient is φ = 13132482048.

The previous prime is 19946190013. The next prime is 19946190023. The reversal of 19946190021 is 12009164991.

It is a happy number.

It is not a de Polignac number, because 19946190021 - 2³ = 19946190013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19946190023) 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, 1045 + ... + 199733.

It is an arithmetic number, because the mean of its divisors is an integer number (1682904300).

Almost surely, 2^19946190021 is an apocalyptic number.

It is an amenable number.

19946190021 is a deficient number, since it is larger than the sum of its proper divisors (6980278779).

19946190021 is a wasteful number, since it uses less digits than its factorization.

19946190021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199108.

The product of its (nonzero) digits is 34992, while the sum is 42.

The spelling of 19946190021 in words is "nineteen billion, nine hundred forty-six million, one hundred ninety thousand, twenty-one".