21788429748751 has 4 divisors (see below), whose sum is σ = 21788826555672. Its totient is φ = 21788032941832.

The previous prime is 21788429748731. The next prime is 21788429748821. The reversal of 21788429748751 is 15784792488712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21788429748751 - 2⁷ = 21788429748623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21788429748731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198321085 + ... + 198430918.

It is an arithmetic number, because the mean of its divisors is an integer number (5447206638918).

Almost surely, 2^{21788429748751} is an apocalyptic number.

21788429748751 is a deficient number, since it is larger than the sum of its proper divisors (396806921).

21788429748751 is an equidigital number, since it uses as much as digits as its factorization.

21788429748751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396806920.

The product of its digits is 505774080, while the sum is 73.

The spelling of 21788429748751 in words is "twenty-one trillion, seven hundred eighty-eight billion, four hundred twenty-nine million, seven hundred forty-eight thousand, seven hundred fifty-one".