21526730 has 16 divisors (see below), whose sum is σ = 38914560. Its totient is φ = 8573712.

The previous prime is 21526727. The next prime is 21526733. The reversal of 21526730 is 3762512.

It is an interprime number because it is at equal distance from previous prime (21526727) and next prime (21526733).

It is a self number, because there is not a number n which added to its sum of digits gives 21526730.

It is not an unprimeable number, because it can be changed into a prime (21526733) 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, 2114 + ... + 6893.

It is an arithmetic number, because the mean of its divisors is an integer number (2432160).

Almost surely, 2^21526730 is an apocalyptic number.

21526730 is a deficient number, since it is larger than the sum of its proper divisors (17387830).

21526730 is a wasteful number, since it uses less digits than its factorization.

21526730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9253.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 21526730 is about 4639.6907224512. The cubic root of 21526730 is about 278.1800758664.

The spelling of 21526730 in words is "twenty-one million, five hundred twenty-six thousand, seven hundred thirty".