21860959 has 4 divisors (see below), whose sum is σ = 22137760. Its totient is φ = 21584160.

The previous prime is 21860941. The next prime is 21860977. The reversal of 21860959 is 95906812.

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

It is an interprime number because it is at equal distance from previous prime (21860941) and next prime (21860977).

It is a cyclic number.

It is not a de Polignac number, because 21860959 - 2¹³ = 21852767 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 (21860939) 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, 138282 + ... + 138439.

It is an arithmetic number, because the mean of its divisors is an integer number (5534440).

Almost surely, 2^21860959 is an apocalyptic number.

21860959 is a deficient number, since it is larger than the sum of its proper divisors (276801).

21860959 is an equidigital number, since it uses as much as digits as its factorization.

21860959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276800.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 21860959 is about 4675.5704464803. The cubic root of 21860959 is about 279.6123845741.

The spelling of 21860959 in words is "twenty-one million, eight hundred sixty thousand, nine hundred fifty-nine".