21405151253 has 2 divisors, whose sum is σ = 21405151254. Its totient is φ = 21405151252.

The previous prime is 21405151247. The next prime is 21405151267. The reversal of 21405151253 is 35215150412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19932357124 + 1472794129 = 141182^2 + 38377^2 .

It is a cyclic number.

It is not a de Polignac number, because 21405151253 - 2¹⁰ = 21405150229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21405151853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10702575626 + 10702575627.

It is an arithmetic number, because the mean of its divisors is an integer number (10702575627).

Almost surely, 2^21405151253 is an apocalyptic number.

It is an amenable number.

21405151253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21405151253 is an equidigital number, since it uses as much as digits as its factorization.

21405151253 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6000, while the sum is 29.

The spelling of 21405151253 in words is "twenty-one billion, four hundred five million, one hundred fifty-one thousand, two hundred fifty-three".