20652391 has 4 divisors (see below), whose sum is σ = 20845512. Its totient is φ = 20459272.

The previous prime is 20652383. The next prime is 20652403. The reversal of 20652391 is 19325602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20652391 - 2³ = 20652383 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 (20652311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96400 + ... + 96613.

It is an arithmetic number, because the mean of its divisors is an integer number (5211378).

Almost surely, 2^20652391 is an apocalyptic number.

20652391 is a deficient number, since it is larger than the sum of its proper divisors (193121).

20652391 is a wasteful number, since it uses less digits than its factorization.

20652391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193120.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 20652391 is about 4544.4901804273. The cubic root of 20652391 is about 274.3616754028.

Adding to 20652391 its reverse (19325602), we get a palindrome (39977993).

The spelling of 20652391 in words is "twenty million, six hundred fifty-two thousand, three hundred ninety-one".