21374728 has 16 divisors (see below), whose sum is σ = 41820480. Its totient is φ = 10222608.

The previous prime is 21374723. The next prime is 21374747. The reversal of 21374728 is 82747312.

It is a junction number, because it is equal to n+sod(n) for n = 21374693 and 21374702.

It is not an unprimeable number, because it can be changed into a prime (21374723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57900 + ... + 58267.

It is an arithmetic number, because the mean of its divisors is an integer number (2613780).

Almost surely, 2^21374728 is an apocalyptic number.

It is an amenable number.

21374728 is a deficient number, since it is larger than the sum of its proper divisors (20445752).

21374728 is a wasteful number, since it uses less digits than its factorization.

21374728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116196 (or 116192 counting only the distinct ones).

The product of its digits is 18816, while the sum is 34.

The square root of 21374728 is about 4623.2810859821. The cubic root of 21374728 is about 277.5237779587.

The spelling of 21374728 in words is "twenty-one million, three hundred seventy-four thousand, seven hundred twenty-eight".