20721267226 has 64 divisors (see below), whose sum is σ = 35914669056. Its totient is φ = 8874236800.

The previous prime is 20721267211. The next prime is 20721267227. The reversal of 20721267226 is 62276212702.

It is not an unprimeable number, because it can be changed into a prime (20721267227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21880485 + ... + 21881431.

It is an arithmetic number, because the mean of its divisors is an integer number (561166704).

Almost surely, 2^20721267226 is an apocalyptic number.

20721267226 is a deficient number, since it is larger than the sum of its proper divisors (15193401830).

20721267226 is a wasteful number, since it uses less digits than its factorization.

20721267226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1587.

The product of its (nonzero) digits is 56448, while the sum is 37.

Adding to 20721267226 its reverse (62276212702), we get a palindrome (82997479928).

The spelling of 20721267226 in words is "twenty billion, seven hundred twenty-one million, two hundred sixty-seven thousand, two hundred twenty-six".