19895721650 has 24 divisors (see below), whose sum is σ = 42292620480. Its totient is φ = 6821390160.

The previous prime is 19895721619. The next prime is 19895721653. The reversal of 19895721650 is 5612759891.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 19895721592 and 19895721601.

It is not an unprimeable number, because it can be changed into a prime (19895721653) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28422110 + ... + 28422809.

It is an arithmetic number, because the mean of its divisors is an integer number (1762192520).

Almost surely, 2^19895721650 is an apocalyptic number.

19895721650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19895721650 is an abundant number, since it is smaller than the sum of its proper divisors (22396898830).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19895721650 is a wasteful number, since it uses less digits than its factorization.

19895721650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56844938 (or 56844933 counting only the distinct ones).

The product of its (nonzero) digits is 1360800, while the sum is 53.

The spelling of 19895721650 in words is "nineteen billion, eight hundred ninety-five million, seven hundred twenty-one thousand, six hundred fifty".