19961808722496 has 63 divisors (see below), whose sum is σ = 57217227841033. Its totient is φ = 6653900497920.

The previous prime is 19961808722489. The next prime is 19961808722563. The reversal of 19961808722496 is 69422780816991.

The square root of 19961808722496 is 4467864.

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

19961808722496 is a `hidden beast` number, since 1 + 9 + 9 + 61 + 8 + 0 + 8 + 72 + 2 + 496 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19790611384896 + 171197337600 = 4448664^2 + 413760^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 107135656 + ... + 107321816.

Almost surely, 2^{19961808722496} is an apocalyptic number.

19961808722496 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

19961808722496 is the 4467864-th square number.

It is an amenable number.

19961808722496 is an abundant number, since it is smaller than the sum of its proper divisors (37255419118537).

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

19961808722496 is an frugal number, since it uses more digits than its factorization.

19961808722496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372340 (or 186166 counting only the distinct ones).

The product of its (nonzero) digits is 188116992, while the sum is 72.

It can be divided in two parts, 19961808 and 722496, that added together give a square (20684304 = 4548²).

The spelling of 19961808722496 in words is "nineteen trillion, nine hundred sixty-one billion, eight hundred eight million, seven hundred twenty-two thousand, four hundred ninety-six".