21464705 has 4 divisors (see below), whose sum is σ = 25757652. Its totient is φ = 17171760.

The previous prime is 21464687. The next prime is 21464711. The reversal of 21464705 is 50746412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7745089 + 13719616 = 2783^2 + 3704^2 .

It is not a de Polignac number, because 21464705 - 2⁸ = 21464449 is a prime.

It is a Duffinian number.

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, 2146466 + ... + 2146475.

It is an arithmetic number, because the mean of its divisors is an integer number (6439413).

Almost surely, 2^21464705 is an apocalyptic number.

It is an amenable number.

21464705 is a deficient number, since it is larger than the sum of its proper divisors (4292947).

21464705 is an equidigital number, since it uses as much as digits as its factorization.

21464705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4292946.

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 21464705 is about 4633.0017267426. The cubic root of 21464705 is about 277.9126452933.

It can be divided in two parts, 2 and 1464705, that multiplied together give a triangular number (2929410 = T₂₄₂₀).

The spelling of 21464705 in words is "twenty-one million, four hundred sixty-four thousand, seven hundred five".