7122121021 has 4 divisors (see below), whose sum is σ = 7207929792. Its totient is φ = 7036312252.

The previous prime is 7122121001. The next prime is 7122121033. The reversal of 7122121021 is 1201212217.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7122121021 - 2¹⁷ = 7121989949 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7122121021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7122121001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42904261 + ... + 42904426.

It is an arithmetic number, because the mean of its divisors is an integer number (1801982448).

Almost surely, 2^7122121021 is an apocalyptic number.

It is an amenable number.

7122121021 is a deficient number, since it is larger than the sum of its proper divisors (85808771).

7122121021 is an equidigital number, since it uses as much as digits as its factorization.

7122121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85808770.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 7122121021 is about 84392.6597578249. The cubic root of 7122121021 is about 1923.9913551917.

Adding to 7122121021 its reverse (1201212217), we get a palindrome (8323333238).

The spelling of 7122121021 in words is "seven billion, one hundred twenty-two million, one hundred twenty-one thousand, twenty-one".