15855401 has 2 divisors, whose sum is σ = 15855402. Its totient is φ = 15855400.

The previous prime is 15855391. The next prime is 15855449. The reversal of 15855401 is 10455851.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8970025 + 6885376 = 2995^2 + 2624^2 .

It is a cyclic number.

It is not a de Polignac number, because 15855401 - 2⁶ = 15855337 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (15855451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7927700 + 7927701.

It is an arithmetic number, because the mean of its divisors is an integer number (7927701).

Almost surely, 2^15855401 is an apocalyptic number.

It is an amenable number.

15855401 is a deficient number, since it is larger than the sum of its proper divisors (1).

15855401 is an equidigital number, since it uses as much as digits as its factorization.

15855401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4000, while the sum is 29.

The square root of 15855401 is about 3981.8841017790. The cubic root of 15855401 is about 251.2228144806. Note that the first 3 decimals are identical.

The spelling of 15855401 in words is "fifteen million, eight hundred fifty-five thousand, four hundred one".