21406514247 has 16 divisors (see below), whose sum is σ = 31719283680. Its totient is φ = 14268341376.

The previous prime is 21406514237. The next prime is 21406514279. The reversal of 21406514247 is 74241560412.

21406514247 is a `hidden beast` number, since 2 + 1 + 406 + 5 + 1 + 4 + 247 = 666.

It is not a de Polignac number, because 21406514247 - 2⁴ = 21406514231 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21406514237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78703 + ... + 221375.

It is an arithmetic number, because the mean of its divisors is an integer number (1982455230).

Almost surely, 2^21406514247 is an apocalyptic number.

21406514247 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21406514247 is a deficient number, since it is larger than the sum of its proper divisors (10312769433).

21406514247 is a wasteful number, since it uses less digits than its factorization.

21406514247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148239 (or 148233 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The spelling of 21406514247 in words is "twenty-one billion, four hundred six million, five hundred fourteen thousand, two hundred forty-seven".