90439997 has 2 divisors, whose sum is σ = 90439998. Its totient is φ = 90439996.

The previous prime is 90439991. The next prime is 90440027. The reversal of 90439997 is 79993409.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81613156 + 8826841 = 9034^2 + 2971^2 .

It is an emirp because it is prime and its reverse (79993409) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90439997 - 2¹² = 90435901 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90439991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45219998 + 45219999.

It is an arithmetic number, because the mean of its divisors is an integer number (45219999).

Almost surely, 2^90439997 is an apocalyptic number.

It is an amenable number.

90439997 is a deficient number, since it is larger than the sum of its proper divisors (1).

90439997 is an equidigital number, since it uses as much as digits as its factorization.

90439997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 551124, while the sum is 50.

The square root of 90439997 is about 9509.9945846462. The cubic root of 90439997 is about 448.8695857868.

The spelling of 90439997 in words is "ninety million, four hundred thirty-nine thousand, nine hundred ninety-seven".