19906388100 has 81 divisors (see below), whose sum is σ = 62408737573. Its totient is φ = 5307241440.

The previous prime is 19906388087. The next prime is 19906388113. The reversal of 19906388100 is 188360991.

The square root of 19906388100 is 141090.

It is a perfect power (a square), and thus also a powerful number.

19906388100 is a `hidden beast` number, since 1 + 9 + 9 + 0 + 638 + 8 + 1 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (19906388087) and next prime (19906388113).

It can be written as a sum of positive squares in only one way, i.e., 7166299716 + 12740088384 = 84654^2 + 112872^2 .

It is a super-2 number, since 2×19906388100² (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 a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4230349 + ... + 4235051.

Almost surely, 2^19906388100 is an apocalyptic number.

19906388100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19906388100 is the 141090-th square number.

It is an amenable number.

19906388100 is an abundant number, since it is smaller than the sum of its proper divisors (42502349473).

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

19906388100 is an equidigital number, since it uses as much as digits as its factorization.

19906388100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9426 (or 4713 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 19906388100 in words is "nineteen billion, nine hundred six million, three hundred eighty-eight thousand, one hundred".