21002213451 has 8 divisors (see below), whose sum is σ = 28003648320. Its totient is φ = 14001127112.

The previous prime is 21002213443. The next prime is 21002213471. The reversal of 21002213451 is 15431220012.

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 21002213451 - 2³ = 21002213443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21002213411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132736 + ... + 244178.

It is an arithmetic number, because the mean of its divisors is an integer number (3500456040).

Almost surely, 2^21002213451 is an apocalyptic number.

21002213451 is a deficient number, since it is larger than the sum of its proper divisors (7001434869).

21002213451 is a wasteful number, since it uses less digits than its factorization.

21002213451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174265.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21002213451 its reverse (15431220012), we get a palindrome (36433433463).

The spelling of 21002213451 in words is "twenty-one billion, two million, two hundred thirteen thousand, four hundred fifty-one".