21731046 has 16 divisors (see below), whose sum is σ = 43509504. Its totient is φ = 7235784.

The previous prime is 21731029. The next prime is 21731051. The reversal of 21731046 is 64013712.

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, 7431 + ... + 9933.

It is an arithmetic number, because the mean of its divisors is an integer number (2719344).

Almost surely, 2^21731046 is an apocalyptic number.

21731046 is an abundant number, since it is smaller than the sum of its proper divisors (21778458).

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

21731046 is a wasteful number, since it uses less digits than its factorization.

21731046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3955.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21731046 is about 4661.6570015393. The cubic root of 21731046 is about 279.0574000937.

Adding to 21731046 its reverse (64013712), we get a palindrome (85744758).

The spelling of 21731046 in words is "twenty-one million, seven hundred thirty-one thousand, forty-six".