21243025574 has 4 divisors (see below), whose sum is σ = 31864538364. Its totient is φ = 10621512786.

The previous prime is 21243025547. The next prime is 21243025577. The reversal of 21243025574 is 47552034212.

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

It is a super-2 number, since 2×21243025574² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243025577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5310756392 + ... + 5310756395.

It is an arithmetic number, because the mean of its divisors is an integer number (7966134591).

Almost surely, 2^21243025574 is an apocalyptic number.

21243025574 is a deficient number, since it is larger than the sum of its proper divisors (10621512790).

21243025574 is a wasteful number, since it uses less digits than its factorization.

21243025574 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10621512789.

The product of its (nonzero) digits is 67200, while the sum is 35.

Adding to 21243025574 its reverse (47552034212), we get a palindrome (68795059786).

The spelling of 21243025574 in words is "twenty-one billion, two hundred forty-three million, twenty-five thousand, five hundred seventy-four".