21004414451 has 8 divisors (see below), whose sum is σ = 21042197904. Its totient is φ = 20966663520.

The previous prime is 21004414439. The next prime is 21004414463. The reversal of 21004414451 is 15441440012.

It is an interprime number because it is at equal distance from previous prime (21004414439) and next prime (21004414463).

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 21004414451 - 2²² = 21000220147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21004414451.

It is not an unprimeable number, because it can be changed into a prime (21004414051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1537985 + ... + 1551581.

It is an arithmetic number, because the mean of its divisors is an integer number (2630274738).

Almost surely, 2^21004414451 is an apocalyptic number.

21004414451 is a deficient number, since it is larger than the sum of its proper divisors (37783453).

21004414451 is a wasteful number, since it uses less digits than its factorization.

21004414451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16261.

The product of its (nonzero) digits is 2560, while the sum is 26.

Adding to 21004414451 its reverse (15441440012), we get a palindrome (36445854463).

The spelling of 21004414451 in words is "twenty-one billion, four million, four hundred fourteen thousand, four hundred fifty-one".