21451964245247 has 8 divisors (see below), whose sum is σ = 21494842346880. Its totient is φ = 21409087057560.

The previous prime is 21451964245241. The next prime is 21451964245277. The reversal of 21451964245247 is 74254246915412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21451964245247 - 2⁴² = 17053917734143 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21451964245192 and 21451964245201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451964245241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65759972 + ... + 66085382.

It is an arithmetic number, because the mean of its divisors is an integer number (2686855293360).

Almost surely, 2^{21451964245247} is an apocalyptic number.

21451964245247 is a deficient number, since it is larger than the sum of its proper divisors (42878101633).

21451964245247 is a wasteful number, since it uses less digits than its factorization.

21451964245247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456973.

The product of its digits is 19353600, while the sum is 56.

The spelling of 21451964245247 in words is "twenty-one trillion, four hundred fifty-one billion, nine hundred sixty-four million, two hundred forty-five thousand, two hundred forty-seven".