90821947 has 2 divisors, whose sum is σ = 90821948. Its totient is φ = 90821946.

The previous prime is 90821933. The next prime is 90821953. The reversal of 90821947 is 74912809.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 90821947 - 2²³ = 82433339 is a prime.

It is not a weakly prime, because it can be changed into another prime (90821987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45410973 + 45410974.

It is an arithmetic number, because the mean of its divisors is an integer number (45410974).

Almost surely, 2^90821947 is an apocalyptic number.

90821947 is a deficient number, since it is larger than the sum of its proper divisors (1).

90821947 is an equidigital number, since it uses as much as digits as its factorization.

90821947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 90821947 is about 9530.0549316360. The cubic root of 90821947 is about 449.5005932922.

The spelling of 90821947 in words is "ninety million, eight hundred twenty-one thousand, nine hundred forty-seven".