21858077 has 4 divisors (see below), whose sum is σ = 22083516. Its totient is φ = 21632640.

The previous prime is 21858029. The next prime is 21858127. The reversal of 21858077 is 77085812.

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 3290596 + 18567481 = 1814^2 + 4309^2 .

It is a cyclic number.

It is not a de Polignac number, because 21858077 - 2¹⁴ = 21841693 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 21858077.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21858017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112574 + ... + 112767.

It is an arithmetic number, because the mean of its divisors is an integer number (5520879).

Almost surely, 2^21858077 is an apocalyptic number.

It is an amenable number.

21858077 is a deficient number, since it is larger than the sum of its proper divisors (225439).

21858077 is an equidigital number, since it uses as much as digits as its factorization.

21858077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225438.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 21858077 is about 4675.2622386343. The cubic root of 21858077 is about 279.6000966364.

The spelling of 21858077 in words is "twenty-one million, eight hundred fifty-eight thousand, seventy-seven".