21674861 has 8 divisors (see below), whose sum is σ = 24147480. Its totient is φ = 19317312.

The previous prime is 21674857. The next prime is 21674899. The reversal of 21674861 is 16847612.

It can be written as a sum of positive squares in 4 ways, for example, as 570025 + 21104836 = 755^2 + 4594^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21674861 - 2² = 21674857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21674561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28370 + ... + 29123.

It is an arithmetic number, because the mean of its divisors is an integer number (3018435).

Almost surely, 2^21674861 is an apocalyptic number.

It is an amenable number.

21674861 is a deficient number, since it is larger than the sum of its proper divisors (2472619).

21674861 is a wasteful number, since it uses less digits than its factorization.

21674861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57535.

The product of its digits is 16128, while the sum is 35.

The square root of 21674861 is about 4655.6268106454. The cubic root of 21674861 is about 278.8166942105.

The spelling of 21674861 in words is "twenty-one million, six hundred seventy-four thousand, eight hundred sixty-one".