20521066 has 8 divisors (see below), whose sum is σ = 30821220. Its totient is φ = 10247328.

The previous prime is 20521063. The next prime is 20521069. The reversal of 20521066 is 66012502.

It is an interprime number because it is at equal distance from previous prime (20521063) and next prime (20521069).

It can be written as a sum of positive squares in 2 ways, for example, as 19847025 + 674041 = 4455^2 + 821^2 .

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

It is a super-2 number, since 2×20521066² = 842228299552712, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20521063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4531 + ... + 7846.

Almost surely, 2^20521066 is an apocalyptic number.

20521066 is a deficient number, since it is larger than the sum of its proper divisors (10300154).

20521066 is a wasteful number, since it uses less digits than its factorization.

20521066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13208.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20521066 is about 4530.0183222588. The cubic root of 20521066 is about 273.7788988347.

Adding to 20521066 its reverse (66012502), we get a palindrome (86533568).

The spelling of 20521066 in words is "twenty million, five hundred twenty-one thousand, sixty-six".