21727402 has 4 divisors (see below), whose sum is σ = 32591106. Its totient is φ = 10863700.

The previous prime is 21727397. The next prime is 21727429. The reversal of 21727402 is 20472712.

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., 12173121 + 9554281 = 3489^2 + 3091^2 .

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, 5431849 + ... + 5431852.

Almost surely, 2^21727402 is an apocalyptic number.

21727402 is a deficient number, since it is larger than the sum of its proper divisors (10863704).

21727402 is a wasteful number, since it uses less digits than its factorization.

21727402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10863703.

The product of its (nonzero) digits is 1568, while the sum is 25.

The square root of 21727402 is about 4661.2661370061. The cubic root of 21727402 is about 279.0418011819.

The spelling of 21727402 in words is "twenty-one million, seven hundred twenty-seven thousand, four hundred two".