90427721 has 2 divisors, whose sum is σ = 90427722. Its totient is φ = 90427720.

The previous prime is 90427703. The next prime is 90427723. The reversal of 90427721 is 12772409.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53655625 + 36772096 = 7325^2 + 6064^2 .

It is a cyclic number.

It is not a de Polignac number, because 90427721 - 2¹⁴ = 90411337 is a prime.

Together with 90427723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (90427723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45213860 + 45213861.

It is an arithmetic number, because the mean of its divisors is an integer number (45213861).

Almost surely, 2^90427721 is an apocalyptic number.

It is an amenable number.

90427721 is a deficient number, since it is larger than the sum of its proper divisors (1).

90427721 is an equidigital number, since it uses as much as digits as its factorization.

90427721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 90427721 is about 9509.3491365077. The cubic root of 90427721 is about 448.8492755533.

The spelling of 90427721 in words is "ninety million, four hundred twenty-seven thousand, seven hundred twenty-one".