19851372961 has 8 divisors (see below), whose sum is σ = 22725546624. Its totient is φ = 16986765120.

The previous prime is 19851372953. The next prime is 19851372967. The reversal of 19851372961 is 16927315891.

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 19851372961 - 2³ = 19851372953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19851372899 and 19851372908.

It is not an unprimeable number, because it can be changed into a prime (19851372967) 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, 2387005 + ... + 2395306.

It is an arithmetic number, because the mean of its divisors is an integer number (2840693328).

Almost surely, 2^19851372961 is an apocalyptic number.

It is an amenable number.

19851372961 is a deficient number, since it is larger than the sum of its proper divisors (2874173663).

19851372961 is an equidigital number, since it uses as much as digits as its factorization.

19851372961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4782911.

The product of its digits is 816480, while the sum is 52.

The spelling of 19851372961 in words is "nineteen billion, eight hundred fifty-one million, three hundred seventy-two thousand, nine hundred sixty-one".