8125909091 has 2 divisors, whose sum is σ = 8125909092. Its totient is φ = 8125909090.

The previous prime is 8125909087. The next prime is 8125909097. The reversal of 8125909091 is 1909095218.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8125909091 - 2² = 8125909087 is a prime.

It is not a weakly prime, because it can be changed into another prime (8125909097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4062954545 + 4062954546.

It is an arithmetic number, because the mean of its divisors is an integer number (4062954546).

Almost surely, 2^8125909091 is an apocalyptic number.

8125909091 is a deficient number, since it is larger than the sum of its proper divisors (1).

8125909091 is an equidigital number, since it uses as much as digits as its factorization.

8125909091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 44.

The square root of 8125909091 is about 90143.8244751131. The cubic root of 8125909091 is about 2010.4378550747.

The spelling of 8125909091 in words is "eight billion, one hundred twenty-five million, nine hundred nine thousand, ninety-one".