21261038 has 16 divisors (see below), whose sum is σ = 33834240. Its totient is φ = 9991800.

The previous prime is 21261029. The next prime is 21261041. The reversal of 21261038 is 83016212.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2843 + ... + 7113.

It is an arithmetic number, because the mean of its divisors is an integer number (2114640).

Almost surely, 2^21261038 is an apocalyptic number.

21261038 is a deficient number, since it is larger than the sum of its proper divisors (12573202).

21261038 is a wasteful number, since it uses less digits than its factorization.

21261038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4423.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21261038 is about 4610.9693124114. The cubic root of 21261038 is about 277.0308627700.

The spelling of 21261038 in words is "twenty-one million, two hundred sixty-one thousand, thirty-eight".