21427085 has 8 divisors (see below), whose sum is σ = 26599320. Its totient is φ = 16550464.

The previous prime is 21427073. The next prime is 21427097. The reversal of 21427085 is 58072412.

It is an interprime number because it is at equal distance from previous prime (21427073) and next prime (21427097).

It can be written as a sum of positive squares in 4 ways, for example, as 7123561 + 14303524 = 2669^2 + 3782^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21427085 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73742 + ... + 74031.

It is an arithmetic number, because the mean of its divisors is an integer number (3324915).

Almost surely, 2^21427085 is an apocalyptic number.

It is an amenable number.

21427085 is a deficient number, since it is larger than the sum of its proper divisors (5172235).

21427085 is a wasteful number, since it uses less digits than its factorization.

21427085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147807.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 21427085 is about 4628.9399434428. The cubic root of 21427085 is about 277.7501896453.

Adding to 21427085 its reverse (58072412), we get a palindrome (79499497).

The spelling of 21427085 in words is "twenty-one million, four hundred twenty-seven thousand, eighty-five".