21140402 has 4 divisors (see below), whose sum is σ = 31710606. Its totient is φ = 10570200.

The previous prime is 21140389. The next prime is 21140423. The reversal of 21140402 is 20404112.

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., 12666481 + 8473921 = 3559^2 + 2911^2 .

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, 5285099 + ... + 5285102.

Almost surely, 2^21140402 is an apocalyptic number.

21140402 is a deficient number, since it is larger than the sum of its proper divisors (10570204).

21140402 is a wasteful number, since it uses less digits than its factorization.

21140402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10570203.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 21140402 is about 4597.8692891382. The cubic root of 21140402 is about 276.5059071558.

Adding to 21140402 its reverse (20404112), we get a palindrome (41544514).

The spelling of 21140402 in words is "twenty-one million, one hundred forty thousand, four hundred two".