15531679109 has 2 divisors, whose sum is σ = 15531679110. Its totient is φ = 15531679108.

The previous prime is 15531679073. The next prime is 15531679127. The reversal of 15531679109 is 90197613551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8264628100 + 7267051009 = 90910^2 + 85247^2 .

It is a cyclic number.

It is not a de Polignac number, because 15531679109 - 2¹² = 15531675013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15531679129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7765839554 + 7765839555.

It is an arithmetic number, because the mean of its divisors is an integer number (7765839555).

Almost surely, 2^15531679109 is an apocalyptic number.

It is an amenable number.

15531679109 is a deficient number, since it is larger than the sum of its proper divisors (1).

15531679109 is an equidigital number, since it uses as much as digits as its factorization.

15531679109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 255150, while the sum is 47.

The spelling of 15531679109 in words is "fifteen billion, five hundred thirty-one million, six hundred seventy-nine thousand, one hundred nine".