90049777661 has 2 divisors, whose sum is σ = 90049777662. Its totient is φ = 90049777660.

The previous prime is 90049777651. The next prime is 90049777703. The reversal of 90049777661 is 16677794009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88658040025 + 1391737636 = 297755^2 + 37306^2 .

It is an emirp because it is prime and its reverse (16677794009) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90049777661 - 2¹⁰ = 90049776637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 90049777597 and 90049777606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90049777651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45024888830 + 45024888831.

It is an arithmetic number, because the mean of its divisors is an integer number (45024888831).

Almost surely, 2^90049777661 is an apocalyptic number.

It is an amenable number.

90049777661 is a deficient number, since it is larger than the sum of its proper divisors (1).

90049777661 is an equidigital number, since it uses as much as digits as its factorization.

90049777661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4000752, while the sum is 56.

The spelling of 90049777661 in words is "ninety billion, forty-nine million, seven hundred seventy-seven thousand, six hundred sixty-one".