20640262 has 4 divisors (see below), whose sum is σ = 30960396. Its totient is φ = 10320130.

The previous prime is 20640247. The next prime is 20640287. The reversal of 20640262 is 26204602.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5160064 + ... + 5160067.

It is an arithmetic number, because the mean of its divisors is an integer number (7740099).

Almost surely, 2^20640262 is an apocalyptic number.

20640262 is a deficient number, since it is larger than the sum of its proper divisors (10320134).

20640262 is a wasteful number, since it uses less digits than its factorization.

20640262 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10320133.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 20640262 is about 4543.1555113159. The cubic root of 20640262 is about 274.3079546750.

Adding to 20640262 its reverse (26204602), we get a palindrome (46844864).

It can be divided in two parts, 20640 and 262, that added together give a palindrome (20902).

The spelling of 20640262 in words is "twenty million, six hundred forty thousand, two hundred sixty-two".