21745472651 has 8 divisors (see below), whose sum is σ = 25192407264. Its totient is φ = 18383647680.

The previous prime is 21745472627. The next prime is 21745472687. The reversal of 21745472651 is 15627454712.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21745472651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21745472351) 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, 21276860 + ... + 21277881.

It is an arithmetic number, because the mean of its divisors is an integer number (3149050908).

Almost surely, 2^21745472651 is an apocalyptic number.

21745472651 is a deficient number, since it is larger than the sum of its proper divisors (3446934613).

21745472651 is an equidigital number, since it uses as much as digits as its factorization.

21745472651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42554821.

The product of its digits is 470400, while the sum is 44.

The spelling of 21745472651 in words is "twenty-one billion, seven hundred forty-five million, four hundred seventy-two thousand, six hundred fifty-one".