21045212455 has 8 divisors (see below), whose sum is σ = 25279290000. Its totient is φ = 16819479936.

The previous prime is 21045212437. The next prime is 21045212473. The reversal of 21045212455 is 55421254012.

It is an interprime number because it is at equal distance from previous prime (21045212437) and next prime (21045212473).

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21045212455 is a prime.

It is a congruent 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, 2080705 + ... + 2090794.

It is an arithmetic number, because the mean of its divisors is an integer number (3159911250).

Almost surely, 2^21045212455 is an apocalyptic number.

21045212455 is a deficient number, since it is larger than the sum of its proper divisors (4234077545).

21045212455 is a wasteful number, since it uses less digits than its factorization.

21045212455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4172513.

The product of its (nonzero) digits is 16000, while the sum is 31.

Adding to 21045212455 its reverse (55421254012), we get a palindrome (76466466467).

The spelling of 21045212455 in words is "twenty-one billion, forty-five million, two hundred twelve thousand, four hundred fifty-five".