21152655 has 12 divisors (see below), whose sum is σ = 36664680. Its totient is φ = 11281392.

The previous prime is 21152591. The next prime is 21152657. The reversal of 21152655 is 55625112.

21152655 is a `hidden beast` number, since 2 + 1 + 1 + 5 + 2 + 655 = 666.

It is not a de Polignac number, because 21152655 - 2⁶ = 21152591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152657) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 234985 + ... + 235074.

It is an arithmetic number, because the mean of its divisors is an integer number (3055390).

Almost surely, 2^21152655 is an apocalyptic number.

21152655 is a deficient number, since it is larger than the sum of its proper divisors (15512025).

21152655 is a wasteful number, since it uses less digits than its factorization.

21152655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470070 (or 470067 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 21152655 is about 4599.2015611408. The cubic root of 21152655 is about 276.5593178797.

Adding to 21152655 its reverse (55625112), we get a palindrome (76777767).

The spelling of 21152655 in words is "twenty-one million, one hundred fifty-two thousand, six hundred fifty-five".