21034402 has 4 divisors (see below), whose sum is σ = 31551606. Its totient is φ = 10517200.

The previous prime is 21034369. The next prime is 21034411. The reversal of 21034402 is 20443012.

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., 20985561 + 48841 = 4581^2 + 221^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5258599 + ... + 5258602.

Almost surely, 2^21034402 is an apocalyptic number.

21034402 is a deficient number, since it is larger than the sum of its proper divisors (10517204).

21034402 is a wasteful number, since it uses less digits than its factorization.

21034402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10517203.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21034402 is about 4586.3277248797. The cubic root of 21034402 is about 276.0429902228.

Adding to 21034402 its reverse (20443012), we get a palindrome (41477414).

The spelling of 21034402 in words is "twenty-one million, thirty-four thousand, four hundred two".