15940861 has 2 divisors, whose sum is σ = 15940862. Its totient is φ = 15940860.

The previous prime is 15940853. The next prime is 15940877. The reversal of 15940861 is 16804951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13645636 + 2295225 = 3694^2 + 1515^2 .

It is a cyclic number.

It is not a de Polignac number, because 15940861 - 2³ = 15940853 is a prime.

It is a super-2 number, since 2×15940861² = 508222098842642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15940811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7970430 + 7970431.

It is an arithmetic number, because the mean of its divisors is an integer number (7970431).

Almost surely, 2^15940861 is an apocalyptic number.

It is an amenable number.

15940861 is a deficient number, since it is larger than the sum of its proper divisors (1).

15940861 is an equidigital number, since it uses as much as digits as its factorization.

15940861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 15940861 is about 3992.6007814456. The cubic root of 15940861 is about 251.6733663894.

The spelling of 15940861 in words is "fifteen million, nine hundred forty thousand, eight hundred sixty-one".