15821081 has 2 divisors, whose sum is σ = 15821082. Its totient is φ = 15821080.

The previous prime is 15821051. The next prime is 15821111. The reversal of 15821081 is 18012851.

15821081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (15821051) and next prime (15821111).

It can be written as a sum of positive squares in only one way, i.e., 15721225 + 99856 = 3965^2 + 316^2 .

It is a cyclic number.

It is not a de Polignac number, because 15821081 - 2¹⁸ = 15558937 is a prime.

It is a super-2 number, since 2×15821081² = 500613208017122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 15821081.

It is not a weakly prime, because it can be changed into another prime (15821011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7910540 + 7910541.

It is an arithmetic number, because the mean of its divisors is an integer number (7910541).

Almost surely, 2^15821081 is an apocalyptic number.

It is an amenable number.

15821081 is a deficient number, since it is larger than the sum of its proper divisors (1).

15821081 is an equidigital number, since it uses as much as digits as its factorization.

15821081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 26.

The square root of 15821081 is about 3977.5722495009. The cubic root of 15821081 is about 251.0414210780.

The spelling of 15821081 in words is "fifteen million, eight hundred twenty-one thousand, eighty-one".