21250253435161 has 2 divisors, whose sum is σ = 21250253435162. Its totient is φ = 21250253435160.

The previous prime is 21250253435101. The next prime is 21250253435171. The reversal of 21250253435161 is 16153435205212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21150984960400 + 99268474761 = 4599020^2 + 315069^2 .

It is a cyclic number.

It is not a de Polignac number, because 21250253435161 - 2²³ = 21250245046553 is a prime.

It is not a weakly prime, because it can be changed into another prime (21250253435101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10625126717580 + 10625126717581.

It is an arithmetic number, because the mean of its divisors is an integer number (10625126717581).

Almost surely, 2^{21250253435161} is an apocalyptic number.

It is an amenable number.

21250253435161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21250253435161 is an equidigital number, since it uses as much as digits as its factorization.

21250253435161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216000, while the sum is 40.

The spelling of 21250253435161 in words is "twenty-one trillion, two hundred fifty billion, two hundred fifty-three million, four hundred thirty-five thousand, one hundred sixty-one".