990000000061 has 2 divisors, whose sum is σ = 990000000062. Its totient is φ = 990000000060.

The previous prime is 990000000053. The next prime is 990000000089. The reversal of 990000000061 is 160000000099.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 937653305625 + 52346694436 = 968325^2 + 228794^2 .

It is a cyclic number.

It is not a de Polignac number, because 990000000061 - 2³ = 990000000053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 989999999963 and 990000000035.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990000010061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495000000030 + 495000000031.

It is an arithmetic number, because the mean of its divisors is an integer number (495000000031).

Almost surely, 2^990000000061 is an apocalyptic number.

It is an amenable number.

990000000061 is a deficient number, since it is larger than the sum of its proper divisors (1).

990000000061 is an equidigital number, since it uses as much as digits as its factorization.

990000000061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 25.

The spelling of 990000000061 in words is "nine hundred ninety billion, sixty-one", and thus it is an aban number.