20640367 has 8 divisors (see below), whose sum is σ = 22575312. Its totient is φ = 18715200.

The previous prime is 20640331. The next prime is 20640391. The reversal of 20640367 is 76304602.

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 20640367 - 2¹⁵ = 20607599 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 (20640307) 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, 2403 + ... + 6859.

It is an arithmetic number, because the mean of its divisors is an integer number (2821914).

Almost surely, 2^20640367 is an apocalyptic number.

20640367 is a deficient number, since it is larger than the sum of its proper divisors (1934945).

20640367 is a wasteful number, since it uses less digits than its factorization.

20640367 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4889.

The product of its (nonzero) digits is 6048, while the sum is 28.

The square root of 20640367 is about 4543.1670671460. The cubic root of 20640367 is about 274.3084198223.

Adding to 20640367 its reverse (76304602), we get a palindrome (96944969).

The spelling of 20640367 in words is "twenty million, six hundred forty thousand, three hundred sixty-seven".