21256020023006 has 16 divisors (see below), whose sum is σ = 31901259774384. Its totient is φ = 10622267857344.

The previous prime is 21256020023003. The next prime is 21256020023023. The reversal of 21256020023006 is 60032002065212.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21256020023006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21256020023003) 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, 39422525 + ... + 39958071.

It is an arithmetic number, because the mean of its divisors is an integer number (1993828735899).

Almost surely, 2^{21256020023006} is an apocalyptic number.

21256020023006 is a deficient number, since it is larger than the sum of its proper divisors (10645239751378).

21256020023006 is a wasteful number, since it uses less digits than its factorization.

21256020023006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546235.

The product of its (nonzero) digits is 8640, while the sum is 29.

Adding to 21256020023006 its reverse (60032002065212), we get a palindrome (81288022088218).

The spelling of 21256020023006 in words is "twenty-one trillion, two hundred fifty-six billion, twenty million, twenty-three thousand, six".