21739016 has 16 divisors (see below), whose sum is σ = 43896300. Its totient is φ = 10033344.

The previous prime is 21739001. The next prime is 21739019. The reversal of 21739016 is 61093712.

It can be written as a sum of positive squares in 2 ways, for example, as 19624900 + 2114116 = 4430^2 + 1454^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21739016.

It is not an unprimeable number, because it can be changed into a prime (21739019) 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 3 ways as a sum of consecutive naturals, for example, 104411 + ... + 104618.

Almost surely, 2^21739016 is an apocalyptic number.

21739016 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21739016 is an abundant number, since it is smaller than the sum of its proper divisors (22157284).

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

21739016 is a wasteful number, since it uses less digits than its factorization.

21739016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209048 (or 209044 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 21739016 is about 4662.5117694221. The cubic root of 21739016 is about 279.0915112855.

The spelling of 21739016 in words is "twenty-one million, seven hundred thirty-nine thousand, sixteen".