20712021 has 8 divisors (see below), whose sum is σ = 30126624. Its totient is φ = 12552720.

The previous prime is 20712019. The next prime is 20712037. The reversal of 20712021 is 12021702.

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

It is not a de Polignac number, because 20712021 - 2¹ = 20712019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20712091) 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 7 ways as a sum of consecutive naturals, for example, 313786 + ... + 313851.

It is an arithmetic number, because the mean of its divisors is an integer number (3765828).

Almost surely, 2^20712021 is an apocalyptic number.

It is an amenable number.

20712021 is a deficient number, since it is larger than the sum of its proper divisors (9414603).

20712021 is a wasteful number, since it uses less digits than its factorization.

20712021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627651.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 20712021 is about 4551.0461434708. The cubic root of 20712021 is about 274.6254780496.

Adding to 20712021 its reverse (12021702), we get a palindrome (32733723).

The spelling of 20712021 in words is "twenty million, seven hundred twelve thousand, twenty-one".