21099436 has 6 divisors (see below), whose sum is σ = 36924020. Its totient is φ = 10549716.

The previous prime is 21099427. The next prime is 21099451. The reversal of 21099436 is 63499012.

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, 2637426 + ... + 2637433.

Almost surely, 2^21099436 is an apocalyptic number.

It is an amenable number.

21099436 is a deficient number, since it is larger than the sum of its proper divisors (15824584).

21099436 is a wasteful number, since it uses less digits than its factorization.

21099436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5274863 (or 5274861 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 21099436 is about 4593.4122392836. The cubic root of 21099436 is about 276.3271867195.

The spelling of 21099436 in words is "twenty-one million, ninety-nine thousand, four hundred thirty-six".