15644499949 has 4 divisors (see below), whose sum is σ = 16847923036. Its totient is φ = 14441076864.

The previous prime is 15644499943. The next prime is 15644499961. The reversal of 15644499949 is 94999444651.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6729741225 + 8914758724 = 82035^2 + 94418^2 .

It is a cyclic number.

It is not a de Polignac number, because 15644499949 - 2⁷ = 15644499821 is a prime.

It is a super-2 number, since 2×15644499949² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15644499943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 601711524 + ... + 601711549.

It is an arithmetic number, because the mean of its divisors is an integer number (4211980759).

Almost surely, 2^15644499949 is an apocalyptic number.

It is an amenable number.

15644499949 is a deficient number, since it is larger than the sum of its proper divisors (1203423087).

15644499949 is a wasteful number, since it uses less digits than its factorization.

15644499949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1203423086.

The product of its digits is 50388480, while the sum is 64.

The spelling of 15644499949 in words is "fifteen billion, six hundred forty-four million, four hundred ninety-nine thousand, nine hundred forty-nine".