21400652461 has 2 divisors, whose sum is σ = 21400652462. Its totient is φ = 21400652460.

The previous prime is 21400652459. The next prime is 21400652477. The reversal of 21400652461 is 16425600412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16087117225 + 5313535236 = 126835^2 + 72894^2 .

It is a cyclic number.

It is not a de Polignac number, because 21400652461 - 2¹ = 21400652459 is a prime.

Together with 21400652459, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21400652761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700326230 + 10700326231.

It is an arithmetic number, because the mean of its divisors is an integer number (10700326231).

Almost surely, 2^21400652461 is an apocalyptic number.

It is an amenable number.

21400652461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21400652461 is an equidigital number, since it uses as much as digits as its factorization.

21400652461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 31.

The spelling of 21400652461 in words is "twenty-one billion, four hundred million, six hundred fifty-two thousand, four hundred sixty-one".