21142635 has 16 divisors (see below), whose sum is σ = 35299584. Its totient is φ = 10785632.

The previous prime is 21142613. The next prime is 21142643. The reversal of 21142635 is 53624112.

It is a cyclic number.

It is not a de Polignac number, because 21142635 - 2⁸ = 21142379 is a prime.

It is a super-2 number, since 2×21142635² = 894022029486450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30297 + ... + 30986.

It is an arithmetic number, because the mean of its divisors is an integer number (2206224).

Almost surely, 2^21142635 is an apocalyptic number.

21142635 is a deficient number, since it is larger than the sum of its proper divisors (14156949).

21142635 is a wasteful number, since it uses less digits than its factorization.

21142635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61314.

The product of its digits is 1440, while the sum is 24.

The square root of 21142635 is about 4598.1121125958. The cubic root of 21142635 is about 276.5156423215.

Adding to 21142635 its reverse (53624112), we get a palindrome (74766747).

The spelling of 21142635 in words is "twenty-one million, one hundred forty-two thousand, six hundred thirty-five".