21423400042 has 8 divisors (see below), whose sum is σ = 35056472832. Its totient is φ = 9737909100.

The previous prime is 21423399997. The next prime is 21423400067. The reversal of 21423400042 is 24000432412.

It is a happy number.

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

It is a Harshad number since it is a multiple of its sum of digits (22), and also a Moran number because the ratio is a prime number: 973790911 = 21423400042 / (2 + 1 + 4 + 2 + 3 + 4 + 0 + 0 + 0 + 4 + 2).

It is a junction number, because it is equal to n+sod(n) for n = 21423399986 and 21423400022.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 486895434 + ... + 486895477.

It is an arithmetic number, because the mean of its divisors is an integer number (4382059104).

Almost surely, 2^21423400042 is an apocalyptic number.

21423400042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21423400042 is a deficient number, since it is larger than the sum of its proper divisors (13633072790).

21423400042 is a wasteful number, since it uses less digits than its factorization.

21423400042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 973790924.

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

Adding to 21423400042 its reverse (24000432412), we get a palindrome (45423832454).

The spelling of 21423400042 in words is "twenty-one billion, four hundred twenty-three million, four hundred thousand, forty-two".