21661044464153 has 2 divisors, whose sum is σ = 21661044464154. Its totient is φ = 21661044464152.

The previous prime is 21661044464099. The next prime is 21661044464167. The reversal of 21661044464153 is 35146444016612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13297166454784 + 8363878009369 = 3646528^2 + 2892037^2 .

It is a cyclic number.

It is not a de Polignac number, because 21661044464153 - 2²² = 21661040269849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21661044464098 and 21661044464107.

It is not a weakly prime, because it can be changed into another prime (21661044464053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10830522232076 + 10830522232077.

It is an arithmetic number, because the mean of its divisors is an integer number (10830522232077).

Almost surely, 2^{21661044464153} is an apocalyptic number.

It is an amenable number.

21661044464153 is a deficient number, since it is larger than the sum of its proper divisors (1).

21661044464153 is an equidigital number, since it uses as much as digits as its factorization.

21661044464153 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1658880, while the sum is 47.

The spelling of 21661044464153 in words is "twenty-one trillion, six hundred sixty-one billion, forty-four million, four hundred sixty-four thousand, one hundred fifty-three".