21675656153 has 2 divisors, whose sum is σ = 21675656154. Its totient is φ = 21675656152.

The previous prime is 21675656147. The next prime is 21675656207. The reversal of 21675656153 is 35165657612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19952410009 + 1723246144 = 141253^2 + 41512^2 .

It is a cyclic number.

It is not a de Polignac number, because 21675656153 - 2⁴ = 21675656137 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21675656098 and 21675656107.

It is not a weakly prime, because it can be changed into another prime (21675056153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10837828076 + 10837828077.

It is an arithmetic number, because the mean of its divisors is an integer number (10837828077).

Almost surely, 2^21675656153 is an apocalyptic number.

It is an amenable number.

21675656153 is a deficient number, since it is larger than the sum of its proper divisors (1).

21675656153 is an equidigital number, since it uses as much as digits as its factorization.

21675656153 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1134000, while the sum is 47.

The spelling of 21675656153 in words is "twenty-one billion, six hundred seventy-five million, six hundred fifty-six thousand, one hundred fifty-three".