21245522542 has 4 divisors (see below), whose sum is σ = 31868283816. Its totient is φ = 10622761270.

The previous prime is 21245522539. The next prime is 21245522563. The reversal of 21245522542 is 24522554212.

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

It is a junction number, because it is equal to n+sod(n) for n = 21245522498 and 21245522507.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5311380634 + ... + 5311380637.

It is an arithmetic number, because the mean of its divisors is an integer number (7967070954).

Almost surely, 2^21245522542 is an apocalyptic number.

21245522542 is a deficient number, since it is larger than the sum of its proper divisors (10622761274).

21245522542 is a wasteful number, since it uses less digits than its factorization.

21245522542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10622761273.

The product of its digits is 64000, while the sum is 34.

The spelling of 21245522542 in words is "twenty-one billion, two hundred forty-five million, five hundred twenty-two thousand, five hundred forty-two".