21012255201 has 16 divisors (see below), whose sum is σ = 32060336000. Its totient is φ = 11991379968.

The previous prime is 21012255197. The next prime is 21012255263. The reversal of 21012255201 is 10255221012.

It is not a de Polignac number, because 21012255201 - 2² = 21012255197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21012255001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 634426 + ... + 666723.

It is an arithmetic number, because the mean of its divisors is an integer number (2003771000).

Almost surely, 2^21012255201 is an apocalyptic number.

21012255201 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21012255201 is a deficient number, since it is larger than the sum of its proper divisors (11048080799).

21012255201 is a wasteful number, since it uses less digits than its factorization.

21012255201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1301928.

The product of its (nonzero) digits is 400, while the sum is 21.

Adding to 21012255201 its reverse (10255221012), we get a palindrome (31267476213).

The spelling of 21012255201 in words is "twenty-one billion, twelve million, two hundred fifty-five thousand, two hundred one".