19898253961 has 4 divisors (see below), whose sum is σ = 19908690192. Its totient is φ = 19887817732.

The previous prime is 19898253941. The next prime is 19898253967. The reversal of 19898253961 is 16935289891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19898253961 - 2²³ = 19889865353 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19898253961.

It is not an unprimeable number, because it can be changed into a prime (19898253967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5215255 + ... + 5219068.

It is an arithmetic number, because the mean of its divisors is an integer number (4977172548).

Almost surely, 2^19898253961 is an apocalyptic number.

It is an amenable number.

19898253961 is a deficient number, since it is larger than the sum of its proper divisors (10436231).

19898253961 is a wasteful number, since it uses less digits than its factorization.

19898253961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10436230.

The product of its digits is 8398080, while the sum is 61.

The spelling of 19898253961 in words is "nineteen billion, eight hundred ninety-eight million, two hundred fifty-three thousand, nine hundred sixty-one".