2015522021 has 2 divisors, whose sum is σ = 2015522022. Its totient is φ = 2015522020.

The previous prime is 2015522017. The next prime is 2015522029. The reversal of 2015522021 is 1202255102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1746069796 + 269452225 = 41786^2 + 16415^2 .

It is a cyclic number.

It is not a de Polignac number, because 2015522021 - 2² = 2015522017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2015521984 and 2015522002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2015522029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1007761010 + 1007761011.

It is an arithmetic number, because the mean of its divisors is an integer number (1007761011).

Almost surely, 2^2015522021 is an apocalyptic number.

It is an amenable number.

2015522021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2015522021 is an equidigital number, since it uses as much as digits as its factorization.

2015522021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 2015522021 is about 44894.5656065408. The cubic root of 2015522021 is about 1263.1720740988.

Adding to 2015522021 its reverse (1202255102), we get a palindrome (3217777123).

The spelling of 2015522021 in words is "two billion, fifteen million, five hundred twenty-two thousand, twenty-one".