222121001001821 has 2 divisors, whose sum is σ = 222121001001822. Its totient is φ = 222121001001820.

The previous prime is 222121001001811. The next prime is 222121001001847. The reversal of 222121001001821 is 128100100121222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174635960700100 + 47485040301721 = 13214990^2 + 6890939^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-222121001001821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (222121001001811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111060500500910 + 111060500500911.

It is an arithmetic number, because the mean of its divisors is an integer number (111060500500911).

Almost surely, 2^{222121001001821} is an apocalyptic number.

It is an amenable number.

222121001001821 is a deficient number, since it is larger than the sum of its proper divisors (1).

222121001001821 is an equidigital number, since it uses as much as digits as its factorization.

222121001001821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 23.

The spelling of 222121001001821 in words is "two hundred twenty-two trillion, one hundred twenty-one billion, one million, one thousand, eight hundred twenty-one".