21154535622061 has 2 divisors, whose sum is σ = 21154535622062. Its totient is φ = 21154535622060.

The previous prime is 21154535622049. The next prime is 21154535622109. The reversal of 21154535622061 is 16022653545112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11074958344836 + 10079577277225 = 3327906^2 + 3174835^2 .

It is a cyclic number.

It is not a de Polignac number, because 21154535622061 - 2³⁵ = 21120175883693 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21154535621999 and 21154535622017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21154535622041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577267811030 + 10577267811031.

It is an arithmetic number, because the mean of its divisors is an integer number (10577267811031).

Almost surely, 2^{21154535622061} is an apocalyptic number.

It is an amenable number.

21154535622061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21154535622061 is an equidigital number, since it uses as much as digits as its factorization.

21154535622061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432000, while the sum is 43.

The spelling of 21154535622061 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred thirty-five million, six hundred twenty-two thousand, sixty-one".