19925144640 has 448 divisors, whose sum is σ = 72341475840. Its totient is φ = 5225472000.

The previous prime is 19925144611. The next prime is 19925144641. The reversal of 19925144640 is 4644152991.

19925144640 is a `hidden beast` number, since 1 + 9 + 92 + 514 + 4 + 6 + 40 = 666.

It is a super-2 number, since 2×19925144640² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (19925144641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 49688440 + ... + 49688840.

Almost surely, 2^19925144640 is an apocalyptic number.

19925144640 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 19925144640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36170737920).

19925144640 is an abundant number, since it is smaller than the sum of its proper divisors (52416331200).

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

19925144640 is an frugal number, since it uses more digits than its factorization.

19925144640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510 (or 482 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 19925144640 in words is "nineteen billion, nine hundred twenty-five million, one hundred forty-four thousand, six hundred forty".