20988071 has 4 divisors (see below), whose sum is σ = 22602552. Its totient is φ = 19373592.

The previous prime is 20988061. The next prime is 20988089. The reversal of 20988071 is 17088902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17088902 = 2 ⋅8544451.

It is a cyclic number.

It is not a de Polignac number, because 20988071 - 2⁶ = 20988007 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 (20988031) 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, 807221 + ... + 807246.

It is an arithmetic number, because the mean of its divisors is an integer number (5650638).

Almost surely, 2^20988071 is an apocalyptic number.

20988071 is a deficient number, since it is larger than the sum of its proper divisors (1614481).

20988071 is a wasteful number, since it uses less digits than its factorization.

20988071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1614480.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 20988071 is about 4581.2739494599. The cubic root of 20988071 is about 275.8401677331.

The spelling of 20988071 in words is "twenty million, nine hundred eighty-eight thousand, seventy-one".