20752121 has 8 divisors (see below), whose sum is σ = 23663304. Its totient is φ = 18028800.

The previous prime is 20752091. The next prime is 20752133. The reversal of 20752121 is 12125702.

It can be written as a sum of positive squares in 4 ways, for example, as 3279721 + 17472400 = 1811^2 + 4180^2 .

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 20752121 - 2⁶ = 20752057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20752093 and 20752102.

It is not an unprimeable number, because it can be changed into a prime (20752021) 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, 46730 + ... + 47171.

It is an arithmetic number, because the mean of its divisors is an integer number (2957913).

Almost surely, 2^20752121 is an apocalyptic number.

It is an amenable number.

20752121 is a deficient number, since it is larger than the sum of its proper divisors (2911183).

20752121 is a wasteful number, since it uses less digits than its factorization.

20752121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93931.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 20752121 is about 4555.4495936186. The cubic root of 20752121 is about 274.8025955202.

Adding to 20752121 its reverse (12125702), we get a palindrome (32877823).

The spelling of 20752121 in words is "twenty million, seven hundred fifty-two thousand, one hundred twenty-one".