15860861 has 2 divisors, whose sum is σ = 15860862. Its totient is φ = 15860860.

The previous prime is 15860857. The next prime is 15860863. The reversal of 15860861 is 16806851.

15860861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14822500 + 1038361 = 3850^2 + 1019^2 .

It is a cyclic number.

It is not a de Polignac number, because 15860861 - 2² = 15860857 is a prime.

It is a super-2 number, since 2×15860861² = 503133823322642, which contains 22 as substring.

Together with 15860863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15860863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7930430 + 7930431.

It is an arithmetic number, because the mean of its divisors is an integer number (7930431).

Almost surely, 2^15860861 is an apocalyptic number.

It is an amenable number.

15860861 is a deficient number, since it is larger than the sum of its proper divisors (1).

15860861 is an equidigital number, since it uses as much as digits as its factorization.

15860861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 15860861 is about 3982.5696478530. The cubic root of 15860861 is about 251.2516483807.

The spelling of 15860861 in words is "fifteen million, eight hundred sixty thousand, eight hundred sixty-one".