2635669921 has 2 divisors, whose sum is σ = 2635669922. Its totient is φ = 2635669920.

The previous prime is 2635669859. The next prime is 2635669937. The reversal of 2635669921 is 1299665362.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1499238400 + 1136431521 = 38720^2 + 33711^2 .

It is a cyclic number.

It is not a de Polignac number, because 2635669921 - 2⁷ = 2635669793 is a prime.

It is not a weakly prime, because it can be changed into another prime (2635669121) 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, 1317834960 + 1317834961.

It is an arithmetic number, because the mean of its divisors is an integer number (1317834961).

Almost surely, 2^2635669921 is an apocalyptic number.

It is an amenable number.

2635669921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2635669921 is an equidigital number, since it uses as much as digits as its factorization.

2635669921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1049760, while the sum is 49.

The square root of 2635669921 is about 51338.7759982647. The cubic root of 2635669921 is about 1381.3286093110.

The spelling of 2635669921 in words is "two billion, six hundred thirty-five million, six hundred sixty-nine thousand, nine hundred twenty-one".