19425320639 has 4 divisors (see below), whose sum is σ = 19425681480. Its totient is φ = 19424959800.

The previous prime is 19425320633. The next prime is 19425320683. The reversal of 19425320639 is 93602352491.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19425320639 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 19425320639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19425320633) 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, 81644 + ... + 213345.

It is an arithmetic number, because the mean of its divisors is an integer number (4856420370).

Almost surely, 2^19425320639 is an apocalyptic number.

19425320639 is a deficient number, since it is larger than the sum of its proper divisors (360841).

19425320639 is an equidigital number, since it uses as much as digits as its factorization.

19425320639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360840.

The product of its (nonzero) digits is 349920, while the sum is 44.

The spelling of 19425320639 in words is "nineteen billion, four hundred twenty-five million, three hundred twenty thousand, six hundred thirty-nine".