19613722401 has 243 divisors, whose sum is σ = 39110210451. Its totient is φ = 9801189216.

The previous prime is 19613722399. The next prime is 19613722411. The reversal of 19613722401 is 10422731691.

The square root of 19613722401 is 140049.

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

19613722401 is a `hidden beast` number, since 19 + 613 + 7 + 2 + 24 + 0 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2901438225 + 16712284176 = 53865^2 + 129276^2 .

It is a tau number, because it is divible by the number of its divisors (243).

It is not a de Polignac number, because 19613722401 - 2¹ = 19613722399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19613722411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 1032301170 + ... + 1032301188.

Almost surely, 2^19613722401 is an apocalyptic number.

19613722401 is the 140049-th square number.

19613722401 is the 70025-th centered octagonal number.

It is an amenable number.

19613722401 is a deficient number, since it is larger than the sum of its proper divisors (19496488050).

19613722401 is an frugal number, since it uses more digits than its factorization.

19613722401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

Multiplying 19613722401 by its sum of digits (36), we get a square (706094006436 = 840294²).

The spelling of 19613722401 in words is "nineteen billion, six hundred thirteen million, seven hundred twenty-two thousand, four hundred one".