19781422021 has 8 divisors (see below), whose sum is σ = 20834397504. Its totient is φ = 18744522720.

The previous prime is 19781421991. The next prime is 19781422033. The reversal of 19781422021 is 12022418791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19781422021 - 2⁹ = 19781421509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19781422051) 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, 4016520 + ... + 4021441.

It is an arithmetic number, because the mean of its divisors is an integer number (2604299688).

Almost surely, 2^19781422021 is an apocalyptic number.

It is an amenable number.

19781422021 is a deficient number, since it is larger than the sum of its proper divisors (1052975483).

19781422021 is a wasteful number, since it uses less digits than its factorization.

19781422021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8038091.

The product of its (nonzero) digits is 16128, while the sum is 37.

The spelling of 19781422021 in words is "nineteen billion, seven hundred eighty-one million, four hundred twenty-two thousand, twenty-one".