21421585061 has 2 divisors, whose sum is σ = 21421585062. Its totient is φ = 21421585060.

The previous prime is 21421585013. The next prime is 21421585109. The reversal of 21421585061 is 16058512412.

It is a balanced prime because it is at equal distance from previous prime (21421585013) and next prime (21421585109).

It can be written as a sum of positive squares in only one way, i.e., 19558022500 + 1863562561 = 139850^2 + 43169^2 .

It is a cyclic number.

It is not a de Polignac number, because 21421585061 - 2²⁶ = 21354476197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21421585961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710792530 + 10710792531.

It is an arithmetic number, because the mean of its divisors is an integer number (10710792531).

Almost surely, 2^21421585061 is an apocalyptic number.

It is an amenable number.

21421585061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421585061 is an equidigital number, since it uses as much as digits as its factorization.

21421585061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19200, while the sum is 35.

The spelling of 21421585061 in words is "twenty-one billion, four hundred twenty-one million, five hundred eighty-five thousand, sixty-one".