21460817 has 16 divisors (see below), whose sum is σ = 27101952. Its totient is φ = 16558080.

The previous prime is 21460793. The next prime is 21460843. The reversal of 21460817 is 71806412.

It is not a de Polignac number, because 21460817 - 2¹⁴ = 21444433 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21460817.

It is not an unprimeable number, because it can be changed into a prime (21460867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1184 + ... + 6657.

It is an arithmetic number, because the mean of its divisors is an integer number (1693872).

Almost surely, 2^21460817 is an apocalyptic number.

It is an amenable number.

21460817 is a deficient number, since it is larger than the sum of its proper divisors (5641135).

21460817 is a wasteful number, since it uses less digits than its factorization.

21460817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7888.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21460817 is about 4632.5821093641. The cubic root of 21460817 is about 277.8958644180.

Subtracting 21460817 from its reverse (71806412), we obtain a triangular number (50345595 = T₁₀₀₃₄).

The spelling of 21460817 in words is "twenty-one million, four hundred sixty thousand, eight hundred seventeen".