90132781 has 2 divisors, whose sum is σ = 90132782. Its totient is φ = 90132780.

The previous prime is 90132769. The next prime is 90132799. The reversal of 90132781 is 18723109.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86769225 + 3363556 = 9315^2 + 1834^2 .

It is an emirp because it is prime and its reverse (18723109) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90132781 - 2⁹ = 90132269 is a prime.

It is a super-2 number, since 2×90132781² = 16247836421587922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90133781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45066390 + 45066391.

It is an arithmetic number, because the mean of its divisors is an integer number (45066391).

Almost surely, 2^90132781 is an apocalyptic number.

It is an amenable number.

90132781 is a deficient number, since it is larger than the sum of its proper divisors (1).

90132781 is an equidigital number, since it uses as much as digits as its factorization.

90132781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 90132781 is about 9493.8285743951. The cubic root of 90132781 is about 448.3607535487.

The spelling of 90132781 in words is "ninety million, one hundred thirty-two thousand, seven hundred eighty-one".