19513575481 has 9 divisors (see below), whose sum is σ = 19656962031. Its totient is φ = 19371230352.

The previous prime is 19513575463. The next prime is 19513575503. The reversal of 19513575481 is 18457531591.

The square root of 19513575481 is 139691.

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

It can be written as a sum of positive squares in only one way, i.e., 18083525625 + 1430049856 = 134475^2 + 37816^2 .

It is not a de Polignac number, because 19513575481 - 2⁷ = 19513575353 is a prime.

It is a super-2 number, since 2×19513575481² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19513575281) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22769205 + ... + 22770061.

Almost surely, 2^19513575481 is an apocalyptic number.

19513575481 is the 139691-st square number.

19513575481 is the 69846-th centered octagonal number.

It is an amenable number.

19513575481 is a deficient number, since it is larger than the sum of its proper divisors (143386550).

19513575481 is an frugal number, since it uses more digits than its factorization.

19513575481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040 (or 1020 counting only the distinct ones).

The product of its digits is 756000, while the sum is 49.

Multiplying 19513575481 by its sum of digits (49), we get a square (956165198569 = 977837²).

The spelling of 19513575481 in words is "nineteen billion, five hundred thirteen million, five hundred seventy-five thousand, four hundred eighty-one".