19797551909136 has 225 divisors, whose sum is σ = 58914379539379. Its totient is φ = 6206155682304.

The previous prime is 19797551909123. The next prime is 19797551909159. The reversal of 19797551909136 is 63190915579791.

The square root of 19797551909136 is 4449444.

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

19797551909136 is a `hidden beast` number, since 1 + 9 + 7 + 9 + 75 + 519 + 0 + 9 + 1 + 36 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6144231307536 + 13653320601600 = 2478756^2 + 3695040^2 .

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 polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 15430671151 + ... + 15430672433.

Almost surely, 2^{19797551909136} is an apocalyptic number.

19797551909136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

19797551909136 is the 4449444-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19797551909136

19797551909136 is an abundant number, since it is smaller than the sum of its proper divisors (39116827630243).

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

19797551909136 is an frugal number, since it uses more digits than its factorization.

19797551909136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2648 (or 1305 counting only the distinct ones).

The product of its (nonzero) digits is 144670050, while the sum is 72.

The spelling of 19797551909136 in words is "nineteen trillion, seven hundred ninety-seven billion, five hundred fifty-one million, nine hundred nine thousand, one hundred thirty-six".