21499746 has 16 divisors (see below), whose sum is σ = 43097184. Its totient is φ = 7150304.

The previous prime is 21499721. The next prime is 21499757. The reversal of 21499746 is 64799412.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21499698 and 21499707.

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, 1035 + ... + 6638.

It is an arithmetic number, because the mean of its divisors is an integer number (2693574).

Almost surely, 2^21499746 is an apocalyptic number.

21499746 is an abundant number, since it is smaller than the sum of its proper divisors (21597438).

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

21499746 is a wasteful number, since it uses less digits than its factorization.

21499746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8145.

The product of its digits is 108864, while the sum is 42.

The square root of 21499746 is about 4636.7818581426. The cubic root of 21499746 is about 278.0637933065.

The spelling of 21499746 in words is "twenty-one million, four hundred ninety-nine thousand, seven hundred forty-six".