21289802 has 8 divisors (see below), whose sum is σ = 32005956. Its totient is φ = 10621152.

The previous prime is 21289781. The next prime is 21289811. The reversal of 21289802 is 20898212.

It can be written as a sum of positive squares in 2 ways, for example, as 21077281 + 212521 = 4591^2 + 461^2 .

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

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, 10733 + ... + 12560.

Almost surely, 2^21289802 is an apocalyptic number.

21289802 is a deficient number, since it is larger than the sum of its proper divisors (10716154).

21289802 is a wasteful number, since it uses less digits than its factorization.

21289802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23752.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 21289802 is about 4614.0873420428. The cubic root of 21289802 is about 277.1557379040.

The spelling of 21289802 in words is "twenty-one million, two hundred eighty-nine thousand, eight hundred two".