21710245 has 8 divisors (see below), whose sum is σ = 26157600. Its totient is φ = 17298000.

The previous prime is 21710239. The next prime is 21710251. The reversal of 21710245 is 54201712.

It is a happy number.

21710245 is nontrivially palindromic in base 2.

It is an interprime number because it is at equal distance from previous prime (21710239) and next prime (21710251).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21710245 - 2⁹ = 21709733 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7395 + ... + 9904.

It is an arithmetic number, because the mean of its divisors is an integer number (3269700).

Almost surely, 2^21710245 is an apocalyptic number.

It is an amenable number.

21710245 is a deficient number, since it is larger than the sum of its proper divisors (4447355).

21710245 is a wasteful number, since it uses less digits than its factorization.

21710245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17555.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21710245 is about 4659.4253937583. The cubic root of 21710245 is about 278.9683335719.

Adding to 21710245 its reverse (54201712), we get a palindrome (75911957).

The spelling of 21710245 in words is "twenty-one million, seven hundred ten thousand, two hundred forty-five".