21289002061 has 2 divisors, whose sum is σ = 21289002062. Its totient is φ = 21289002060.

The previous prime is 21289002043. The next prime is 21289002079. The reversal of 21289002061 is 16020098212.

It is a balanced prime because it is at equal distance from previous prime (21289002043) and next prime (21289002079).

It can be written as a sum of positive squares in only one way, i.e., 20497648900 + 791353161 = 143170^2 + 28131^2 .

It is a cyclic number.

It is not a de Polignac number, because 21289002061 - 2⁷ = 21289001933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21289002041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10644501030 + 10644501031.

It is an arithmetic number, because the mean of its divisors is an integer number (10644501031).

Almost surely, 2^21289002061 is an apocalyptic number.

It is an amenable number.

21289002061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21289002061 is an equidigital number, since it uses as much as digits as its factorization.

21289002061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 31.

The spelling of 21289002061 in words is "twenty-one billion, two hundred eighty-nine million, two thousand, sixty-one".