19490672881 has 3 divisors (see below), whose sum is σ = 19490812491. Its totient is φ = 19490533272.

The previous prime is 19490672869. The next prime is 19490672899. The reversal of 19490672881 is 18827609491.

It is a happy number.

The square root of 19490672881 is 139609.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 18812591281 + 678081600 = 137159^2 + 26040^2 .

It is not a de Polignac number, because 19490672881 - 2¹⁷ = 19490541809 is a prime.

It is a super-2 number, since 2×19490672881² (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 (19490672681) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 69805 + ... + 209413.

It is an arithmetic number, because the mean of its divisors is an integer number (6496937497).

Almost surely, 2^19490672881 is an apocalyptic number.

19490672881 is the 139609-th square number.

19490672881 is the 69805-th centered octagonal number.

It is an amenable number.

19490672881 is a deficient number, since it is larger than the sum of its proper divisors (139610).

19490672881 is an frugal number, since it uses more digits than its factorization.

19490672881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279218 (or 139609 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 55.

The spelling of 19490672881 in words is "nineteen billion, four hundred ninety million, six hundred seventy-two thousand, eight hundred eighty-one".