21710516 has 6 divisors (see below), whose sum is σ = 37993410. Its totient is φ = 10855256.

The previous prime is 21710503. The next prime is 21710519. The reversal of 21710516 is 61501712.

It can be written as a sum of positive squares in only one way, i.e., 20702500 + 1008016 = 4550^2 + 1004^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21710491 and 21710500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21710519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2713811 + ... + 2713818.

It is an arithmetic number, because the mean of its divisors is an integer number (6332235).

Almost surely, 2^21710516 is an apocalyptic number.

It is an amenable number.

21710516 is a deficient number, since it is larger than the sum of its proper divisors (16282894).

21710516 is a wasteful number, since it uses less digits than its factorization.

21710516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5427633 (or 5427631 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 21710516 is about 4659.4544745066. The cubic root of 21710516 is about 278.9694943158.

The spelling of 21710516 in words is "twenty-one million, seven hundred ten thousand, five hundred sixteen".