19724951489 has 8 divisors (see below), whose sum is σ = 20956613160. Its totient is φ = 18530055936.

The previous prime is 19724951483. The next prime is 19724951507. The reversal of 19724951489 is 98415942791.

It can be written as a sum of positive squares in 4 ways, for example, as 14132454400 + 5592497089 = 118880^2 + 74783^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19724951489 is a prime.

It is a super-2 number, since 2×19724951489² (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 (19724951483) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9190424 + ... + 9192569.

It is an arithmetic number, because the mean of its divisors is an integer number (2619576645).

Almost surely, 2^19724951489 is an apocalyptic number.

It is an amenable number.

19724951489 is a deficient number, since it is larger than the sum of its proper divisors (1231661671).

19724951489 is a wasteful number, since it uses less digits than its factorization.

19724951489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18383059.

The product of its digits is 6531840, while the sum is 59.

The spelling of 19724951489 in words is "nineteen billion, seven hundred twenty-four million, nine hundred fifty-one thousand, four hundred eighty-nine".