21860671 has 4 divisors (see below), whose sum is σ = 24983632. Its totient is φ = 18737712.

The previous prime is 21860651. The next prime is 21860689. The reversal of 21860671 is 17606812.

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

It is not a de Polignac number, because 21860671 - 2⁷ = 21860543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21860651) 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, 1561470 + ... + 1561483.

It is an arithmetic number, because the mean of its divisors is an integer number (6245908).

Almost surely, 2^21860671 is an apocalyptic number.

21860671 is a deficient number, since it is larger than the sum of its proper divisors (3122961).

21860671 is an equidigital number, since it uses as much as digits as its factorization.

21860671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3122960.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21860671 is about 4675.5396479979. The cubic root of 21860671 is about 279.6111566817.

The spelling of 21860671 in words is "twenty-one million, eight hundred sixty thousand, six hundred seventy-one".