15681966749 has 16 divisors (see below), whose sum is σ = 16900980480. Its totient is φ = 14503910400.

The previous prime is 15681966737. The next prime is 15681966757. The reversal of 15681966749 is 94766918651.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15681966749 is a prime.

It is a super-2 number, since 2×15681966749² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 15681966691 and 15681966700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15681966709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 336197 + ... + 379989.

It is an arithmetic number, because the mean of its divisors is an integer number (1056311280).

Almost surely, 2^15681966749 is an apocalyptic number.

15681966749 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

15681966749 is a deficient number, since it is larger than the sum of its proper divisors (1219013731).

15681966749 is a wasteful number, since it uses less digits than its factorization.

15681966749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44260.

The product of its digits is 19595520, while the sum is 62.

The spelling of 15681966749 in words is "fifteen billion, six hundred eighty-one million, nine hundred sixty-six thousand, seven hundred forty-nine".