19857488400 has 180 divisors, whose sum is σ = 70079733360. Its totient is φ = 5205523200.

The previous prime is 19857488377. The next prime is 19857488407. The reversal of 19857488400 is 488475891.

19857488400 is a `hidden beast` number, since 1 + 98 + 5 + 74 + 88 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×19857488400² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19857488407) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 165655 + ... + 259145.

It is an arithmetic number, because the mean of its divisors is an integer number (389331852).

Almost surely, 2^19857488400 is an apocalyptic number.

19857488400 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 19857488400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35039866680).

19857488400 is an abundant number, since it is smaller than the sum of its proper divisors (50222244960).

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

19857488400 is a wasteful number, since it uses less digits than its factorization.

19857488400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93574 (or 93560 counting only the distinct ones).

The product of its (nonzero) digits is 2580480, while the sum is 54.

It can be divided in two parts, 1985 and 7488400, that added together give a triangular number (7490385 = T₃₈₇₀).

The spelling of 19857488400 in words is "nineteen billion, eight hundred fifty-seven million, four hundred eighty-eight thousand, four hundred".