19939975776400 has 135 divisors (see below), whose sum is σ = 49621123688331. Its totient is φ = 7699955907840.

The previous prime is 19939975776359. The next prime is 19939975776407. The reversal of 19939975776400 is 467757993991.

The square root of 19939975776400 is 4465420.

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

It can be written as a sum of positive squares in 4 ways, for example, as 274085755024 + 19665890021376 = 523532^2 + 4434624^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19939975776407) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2589939751 + ... + 2589947449.

Almost surely, 2^{19939975776400} is an apocalyptic number.

19939975776400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19939975776400 is the 4465420-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19939975776400

19939975776400 is an abundant number, since it is smaller than the sum of its proper divisors (29681147911931).

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

19939975776400 is an frugal number, since it uses more digits than its factorization.

19939975776400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15474 (or 7735 counting only the distinct ones).

The product of its (nonzero) digits is 810152280, while the sum is 76.

The spelling of 19939975776400 in words is "nineteen trillion, nine hundred thirty-nine billion, nine hundred seventy-five million, seven hundred seventy-six thousand, four hundred".