1011211010021 has 2 divisors, whose sum is σ = 1011211010022. Its totient is φ = 1011211010020.

The previous prime is 1011211010003. The next prime is 1011211010057. The reversal of 1011211010021 is 1200101121101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 750484353025 + 260726656996 = 866305^2 + 510614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1011211010021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1011211009984 and 1011211010011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1011211070021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505605505010 + 505605505011.

It is an arithmetic number, because the mean of its divisors is an integer number (505605505011).

Almost surely, 2^{1011211010021} is an apocalyptic number.

It is an amenable number.

1011211010021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011211010021 is an equidigital number, since it uses as much as digits as its factorization.

1011211010021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 1011211010021 its reverse (1200101121101), we get a palindrome (2211312131122).

The spelling of 1011211010021 in words is "one trillion, eleven billion, two hundred eleven million, ten thousand, twenty-one".