21526642 has 16 divisors (see below), whose sum is σ = 33580800. Its totient is φ = 10337040.

The previous prime is 21526633. The next prime is 21526649. The reversal of 21526642 is 24662512.

It is a pancake number, because a pancake can be divided into 21526642 parts by 6561 straight cuts.

It is a self number, because there is not a number n which added to its sum of digits gives 21526642.

It is not an unprimeable number, because it can be changed into a prime (21526649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11359 + ... + 13117.

It is an arithmetic number, because the mean of its divisors is an integer number (2098800).

Almost surely, 2^21526642 is an apocalyptic number.

21526642 is a deficient number, since it is larger than the sum of its proper divisors (12054158).

21526642 is a wasteful number, since it uses less digits than its factorization.

21526642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2001.

The product of its digits is 5760, while the sum is 28.

The square root of 21526642 is about 4639.6812390508. The cubic root of 21526642 is about 278.1796968047.

The spelling of 21526642 in words is "twenty-one million, five hundred twenty-six thousand, six hundred forty-two".