19812857400 has 432 divisors, whose sum is σ = 80794761840. Its totient is φ = 4261478400.

The previous prime is 19812857387. The next prime is 19812857413. The reversal of 19812857400 is 475821891.

19812857400 is a `hidden beast` number, since 198 + 1 + 2 + 8 + 57 + 400 = 666.

It is an interprime number because it is at equal distance from previous prime (19812857387) and next prime (19812857413).

It is a super-3 number, since 3×19812857400³ (a number of 32 digits) contains 333 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 3638680 + ... + 3644120.

Almost surely, 2^19812857400 is an apocalyptic number.

19812857400 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 19812857400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40397380920).

19812857400 is an abundant number, since it is smaller than the sum of its proper divisors (60981904440).

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

19812857400 is a wasteful number, since it uses less digits than its factorization.

19812857400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5504 (or 5475 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 19812857400 in words is "nineteen billion, eight hundred twelve million, eight hundred fifty-seven thousand, four hundred".