15991249196837 has 16 divisors (see below), whose sum is σ = 17061089194800. Its totient is φ = 14935946539008.

The previous prime is 15991249196777. The next prime is 15991249196891. The reversal of 15991249196837 is 73869194219951.

It is a Cunningham number, because it is equal to 3998906²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 83922613636 + 15907326583201 = 289694^2 + 3988399^2 .

It is a cyclic number.

It is not a de Polignac number, because 15991249196837 - 2³² = 15986954229541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15991249106837) 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, 98768 + ... + 5656169.

It is an arithmetic number, because the mean of its divisors is an integer number (1066318074675).

Almost surely, 2^{15991249196837} is an apocalyptic number.

15991249196837 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

15991249196837 is a deficient number, since it is larger than the sum of its proper divisors (1069839997963).

15991249196837 is a wasteful number, since it uses less digits than its factorization.

15991249196837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5756200.

The product of its digits is 264539520, while the sum is 74.

The spelling of 15991249196837 in words is "fifteen trillion, nine hundred ninety-one billion, two hundred forty-nine million, one hundred ninety-six thousand, eight hundred thirty-seven".