19967971920 has 360 divisors, whose sum is σ = 69234381216. Its totient is φ = 4756018176.

The previous prime is 19967971901. The next prime is 19967971921. The reversal of 19967971920 is 2917976991.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19967971921) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 186616507 + ... + 186616613.

Almost surely, 2^19967971920 is an apocalyptic number.

19967971920 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 19967971920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34617190608).

19967971920 is an abundant number, since it is smaller than the sum of its proper divisors (49266409296).

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

19967971920 is a wasteful number, since it uses less digits than its factorization.

19967971920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 3857868, while the sum is 60.

The spelling of 19967971920 in words is "nineteen billion, nine hundred sixty-seven million, nine hundred seventy-one thousand, nine hundred twenty".