21298402 has 4 divisors (see below), whose sum is σ = 31947606. Its totient is φ = 10649200.

The previous prime is 21298397. The next prime is 21298427. The reversal of 21298402 is 20489212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 13905441 + 7392961 = 3729^2 + 2719^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5324599 + ... + 5324602.

Almost surely, 2^21298402 is an apocalyptic number.

21298402 is a deficient number, since it is larger than the sum of its proper divisors (10649204).

21298402 is a wasteful number, since it uses less digits than its factorization.

21298402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10649203.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21298402 is about 4615.0191765582. The cubic root of 21298402 is about 277.1930518329.

The spelling of 21298402 in words is "twenty-one million, two hundred ninety-eight thousand, four hundred two".