21180052 has 12 divisors (see below), whose sum is σ = 37314900. Its totient is φ = 10518656.

The previous prime is 21180043. The next prime is 21180053. The reversal of 21180052 is 25008112.

It can be written as a sum of positive squares in 2 ways, for example, as 9647236 + 11532816 = 3106^2 + 3396^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21180053) 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, 17173 + ... + 18364.

It is an arithmetic number, because the mean of its divisors is an integer number (3109575).

Almost surely, 2^21180052 is an apocalyptic number.

It is an amenable number.

21180052 is a deficient number, since it is larger than the sum of its proper divisors (16134848).

21180052 is a wasteful number, since it uses less digits than its factorization.

21180052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35690 (or 35688 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 21180052 is about 4602.1790491027. The cubic root of 21180052 is about 276.6786665978.

Adding to 21180052 its reverse (25008112), we get a palindrome (46188164).

The spelling of 21180052 in words is "twenty-one million, one hundred eighty thousand, fifty-two".