21511244212001 has 2 divisors, whose sum is σ = 21511244212002. Its totient is φ = 21511244212000.

The previous prime is 21511244211983. The next prime is 21511244212039. The reversal of 21511244212001 is 10021244211512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21468580896400 + 42663315601 = 4633420^2 + 206551^2 .

It is a cyclic number.

It is not a de Polignac number, because 21511244212001 - 2²⁶ = 21511177103137 is a prime.

It is not a weakly prime, because it can be changed into another prime (21511244202001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10755622106000 + 10755622106001.

It is an arithmetic number, because the mean of its divisors is an integer number (10755622106001).

Almost surely, 2^{21511244212001} is an apocalyptic number.

It is an amenable number.

21511244212001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21511244212001 is an equidigital number, since it uses as much as digits as its factorization.

21511244212001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1280, while the sum is 26.

Adding to 21511244212001 its reverse (10021244211512), we get a palindrome (31532488423513).

The spelling of 21511244212001 in words is "twenty-one trillion, five hundred eleven billion, two hundred forty-four million, two hundred twelve thousand, one".