21710736 has 30 divisors (see below), whose sum is σ = 60760310. Its totient is φ = 7236864.

The previous prime is 21710723. The next prime is 21710737. The reversal of 21710736 is 63701712.

It can be written as a sum of positive squares in only one way, i.e., 21678336 + 32400 = 4656^2 + 180^2 .

It is not an unprimeable number, because it can be changed into a prime (21710737) by changing a digit.

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 in 5 ways as a sum of consecutive naturals, for example, 75241 + ... + 75528.

Almost surely, 2^21710736 is an apocalyptic number.

It is an amenable number.

21710736 is an abundant number, since it is smaller than the sum of its proper divisors (39049574).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21710736 is a wasteful number, since it uses less digits than its factorization.

21710736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150783 (or 150774 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 21710736 is about 4659.4780823607. The cubic root of 21710736 is about 278.9704366101.

The spelling of 21710736 in words is "twenty-one million, seven hundred ten thousand, seven hundred thirty-six".