21842658 has 12 divisors (see below), whose sum is σ = 47325798. Its totient is φ = 7280880.

The previous prime is 21842651. The next prime is 21842669. The reversal of 21842658 is 85624812.

It can be written as a sum of positive squares in only one way, i.e., 12089529 + 9753129 = 3477^2 + 3123^2 .

It is not an unprimeable number, because it can be changed into a prime (21842651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 606723 + ... + 606758.

Almost surely, 2^21842658 is an apocalyptic number.

21842658 is an abundant number, since it is smaller than the sum of its proper divisors (25483140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21842658 is a wasteful number, since it uses less digits than its factorization.

21842658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1213489 (or 1213486 counting only the distinct ones).

The product of its digits is 30720, while the sum is 36.

The square root of 21842658 is about 4673.6129493145. The cubic root of 21842658 is about 279.5343365362.

It can be divided in two parts, 21842 and 658, that added together give a square (22500 = 150²).

The spelling of 21842658 in words is "twenty-one million, eight hundred forty-two thousand, six hundred fifty-eight".