21052061 has 8 divisors (see below), whose sum is σ = 22118400. Its totient is φ = 19998352.

The previous prime is 21052051. The next prime is 21052063. The reversal of 21052061 is 16025012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21052061 - 2¹⁸ = 20789917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052063) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 356 + ... + 6498.

It is an arithmetic number, because the mean of its divisors is an integer number (2764800).

Almost surely, 2^21052061 is an apocalyptic number.

It is an amenable number.

21052061 is a deficient number, since it is larger than the sum of its proper divisors (1066339).

21052061 is a wasteful number, since it uses less digits than its factorization.

21052061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6315.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21052061 is about 4588.2524995907. The cubic root of 21052061 is about 276.1202173556.

Adding to 21052061 its reverse (16025012), we get a palindrome (37077073).

The spelling of 21052061 in words is "twenty-one million, fifty-two thousand, sixty-one".