91020949 has 2 divisors, whose sum is σ = 91020950. Its totient is φ = 91020948.

The previous prime is 91020947. The next prime is 91020961. The reversal of 91020949 is 94902019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87048900 + 3972049 = 9330^2 + 1993^2 .

It is an emirp because it is prime and its reverse (94902019) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91020949 - 2¹ = 91020947 is a prime.

Together with 91020947, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91020947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45510474 + 45510475.

It is an arithmetic number, because the mean of its divisors is an integer number (45510475).

Almost surely, 2^91020949 is an apocalyptic number.

It is an amenable number.

91020949 is a deficient number, since it is larger than the sum of its proper divisors (1).

91020949 is an equidigital number, since it uses as much as digits as its factorization.

91020949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 91020949 is about 9540.4899769351. The cubic root of 91020949 is about 449.8286574014.

The spelling of 91020949 in words is "ninety-one million, twenty thousand, nine hundred forty-nine".