21150656 has 28 divisors (see below), whose sum is σ = 42415968. Its totient is φ = 10463232.

The previous prime is 21150653. The next prime is 21150659. The reversal of 21150656 is 65605112.

It is an interprime number because it is at equal distance from previous prime (21150653) and next prime (21150659).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150653) 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 3 ways as a sum of consecutive naturals, for example, 4505 + ... + 7911.

It is an arithmetic number, because the mean of its divisors is an integer number (1514856).

Almost surely, 2^21150656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21150656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21207984).

21150656 is an abundant number, since it is smaller than the sum of its proper divisors (21265312).

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

21150656 is an equidigital number, since it uses as much as digits as its factorization.

21150656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3516 (or 3506 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 21150656 is about 4598.9842356764. The cubic root of 21150656 is about 276.5506056638.

Adding to 21150656 its reverse (65605112), we get a palindrome (86755768).

The spelling of 21150656 in words is "twenty-one million, one hundred fifty thousand, six hundred fifty-six".