21003240442 has 8 divisors (see below), whose sum is σ = 31752930816. Its totient is φ = 10418930172.

The previous prime is 21003240431. The next prime is 21003240449. The reversal of 21003240442 is 24404230012.

It is a happy number.

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

It is a super-2 number, since 2×21003240442² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21003240449) 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, 41344708 + ... + 41345215.

It is an arithmetic number, because the mean of its divisors is an integer number (3969116352).

Almost surely, 2^21003240442 is an apocalyptic number.

21003240442 is a deficient number, since it is larger than the sum of its proper divisors (10749690374).

21003240442 is a wasteful number, since it uses less digits than its factorization.

21003240442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82690052.

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21003240442 its reverse (24404230012), we get a palindrome (45407470454).

The spelling of 21003240442 in words is "twenty-one billion, three million, two hundred forty thousand, four hundred forty-two".