21405151247 has 2 divisors, whose sum is σ = 21405151248. Its totient is φ = 21405151246.

The previous prime is 21405151241. The next prime is 21405151253. The reversal of 21405151247 is 74215150412.

It is a balanced prime because it is at equal distance from previous prime (21405151241) and next prime (21405151253).

It is a cyclic number.

It is not a de Polignac number, because 21405151247 - 2¹⁰ = 21405150223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21405151241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10702575623 + 10702575624.

It is an arithmetic number, because the mean of its divisors is an integer number (10702575624).

Almost surely, 2^21405151247 is an apocalyptic number.

21405151247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21405151247 is an equidigital number, since it uses as much as digits as its factorization.

21405151247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11200, while the sum is 32.

The spelling of 21405151247 in words is "twenty-one billion, four hundred five million, one hundred fifty-one thousand, two hundred forty-seven".