21004142345 has 8 divisors (see below), whose sum is σ = 26687616264. Its totient is φ = 15814883584.

The previous prime is 21004142333. The next prime is 21004142353. The reversal of 21004142345 is 54324140012.

It can be written as a sum of positive squares in 4 ways, for example, as 485585296 + 20518557049 = 22036^2 + 143243^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21004142345 - 2¹⁶ = 21004076809 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123553694 + ... + 123553863.

It is an arithmetic number, because the mean of its divisors is an integer number (3335952033).

Almost surely, 2^21004142345 is an apocalyptic number.

It is an amenable number.

21004142345 is a deficient number, since it is larger than the sum of its proper divisors (5683473919).

21004142345 is a wasteful number, since it uses less digits than its factorization.

21004142345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247107579.

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21004142345 its reverse (54324140012), we get a palindrome (75328282357).

The spelling of 21004142345 in words is "twenty-one billion, four million, one hundred forty-two thousand, three hundred forty-five".