19964257920 has 768 divisors, whose sum is σ = 76347048960. Its totient is φ = 4976640000.

The previous prime is 19964257909. The next prime is 19964257931. The reversal of 19964257920 is 2975246991.

19964257920 is a `hidden beast` number, since 1 + 9 + 9 + 6 + 42 + 579 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (19964257909) and next prime (19964257931).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 197665870 + ... + 197665970.

It is an arithmetic number, because the mean of its divisors is an integer number (99410220).

Almost surely, 2^19964257920 is an apocalyptic number.

19964257920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19964257920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38173524480).

19964257920 is an abundant number, since it is smaller than the sum of its proper divisors (56382791040).

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

19964257920 is a wasteful number, since it uses less digits than its factorization.

19964257920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 54.

The spelling of 19964257920 in words is "nineteen billion, nine hundred sixty-four million, two hundred fifty-seven thousand, nine hundred twenty".