15691061 has 2 divisors, whose sum is σ = 15691062. Its totient is φ = 15691060.

The previous prime is 15691043. The next prime is 15691073. The reversal of 15691061 is 16019651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12780625 + 2910436 = 3575^2 + 1706^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15691061 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15691261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7845530 + 7845531.

It is an arithmetic number, because the mean of its divisors is an integer number (7845531).

Almost surely, 2^15691061 is an apocalyptic number.

15691061 is the 1772-nd centered decagonal number.

It is an amenable number.

15691061 is a deficient number, since it is larger than the sum of its proper divisors (1).

15691061 is an equidigital number, since it uses as much as digits as its factorization.

15691061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 15691061 is about 3961.1943905847. The cubic root of 15691061 is about 250.3518299638.

The spelling of 15691061 in words is "fifteen million, six hundred ninety-one thousand, sixty-one".