21707146 has 8 divisors (see below), whose sum is σ = 32973120. Its totient is φ = 10716108.

The previous prime is 21707137. The next prime is 21707159. The reversal of 21707146 is 64170712.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68536 + ... + 68851.

It is an arithmetic number, because the mean of its divisors is an integer number (4121640).

Almost surely, 2^21707146 is an apocalyptic number.

21707146 is a deficient number, since it is larger than the sum of its proper divisors (11265974).

21707146 is a wasteful number, since it uses less digits than its factorization.

21707146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137468.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 21707146 is about 4659.0928301548. The cubic root of 21707146 is about 278.9550592859.

Adding to 21707146 its reverse (64170712), we get a palindrome (85877858).

It can be divided in two parts, 2170 and 7146, that added together give a triangular number (9316 = T₁₃₆).

The spelling of 21707146 in words is "twenty-one million, seven hundred seven thousand, one hundred forty-six".