20151091 has 2 divisors, whose sum is σ = 20151092. Its totient is φ = 20151090.

The previous prime is 20151067. The next prime is 20151097. The reversal of 20151091 is 19015102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20151091 - 2¹¹ = 20149043 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20151097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10075545 + 10075546.

It is an arithmetic number, because the mean of its divisors is an integer number (10075546).

Almost surely, 2^20151091 is an apocalyptic number.

20151091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20151091 is an equidigital number, since it uses as much as digits as its factorization.

20151091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90, while the sum is 19.

The square root of 20151091 is about 4488.9966584973. The cubic root of 20151091 is about 272.1235876883.

Adding to 20151091 its reverse (19015102), we get a palindrome (39166193).

It can be divided in two parts, 201510 and 91, that added together give a square (201601 = 449²).

The spelling of 20151091 in words is "twenty million, one hundred fifty-one thousand, ninety-one".