19551720425 has 12 divisors (see below), whose sum is σ = 24384278220. Its totient is φ = 15550960320.

The previous prime is 19551720371. The next prime is 19551720431. The reversal of 19551720425 is 52402715591.

It can be written as a sum of positive squares in 6 ways, for example, as 2027520784 + 17524199641 = 45028^2 + 132379^2 .

It is not a de Polignac number, because 19551720425 - 2²⁰ = 19550671849 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2255990 + ... + 2264639.

It is an arithmetic number, because the mean of its divisors is an integer number (2032023185).

Almost surely, 2^19551720425 is an apocalyptic number.

It is an amenable number.

19551720425 is a deficient number, since it is larger than the sum of its proper divisors (4832557795).

19551720425 is a wasteful number, since it uses less digits than its factorization.

19551720425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4520812 (or 4520807 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 41.

The spelling of 19551720425 in words is "nineteen billion, five hundred fifty-one million, seven hundred twenty thousand, four hundred twenty-five".