21421713456 has 240 divisors, whose sum is σ = 72152694432. Its totient is φ = 5845708800.

The previous prime is 21421713431. The next prime is 21421713463. The reversal of 21421713456 is 65431712412.

21421713456 is a `hidden beast` number, since 2 + 142 + 171 + 345 + 6 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21421713456.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 831586 + ... + 856958.

Almost surely, 2^21421713456 is an apocalyptic number.

21421713456 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21421713456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36076347216).

21421713456 is an abundant number, since it is smaller than the sum of its proper divisors (50730980976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21421713456 is a wasteful number, since it uses less digits than its factorization.

21421713456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25452 (or 25443 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The spelling of 21421713456 in words is "twenty-one billion, four hundred twenty-one million, seven hundred thirteen thousand, four hundred fifty-six".