2215406021 has 2 divisors, whose sum is σ = 2215406022. Its totient is φ = 2215406020.

The previous prime is 2215406009. The next prime is 2215406071. The reversal of 2215406021 is 1206045122.

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., 1696204225 + 519201796 = 41185^2 + 22786^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2215406021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2215406071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1107703010 + 1107703011.

It is an arithmetic number, because the mean of its divisors is an integer number (1107703011).

Almost surely, 2^2215406021 is an apocalyptic number.

It is an amenable number.

2215406021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2215406021 is an equidigital number, since it uses as much as digits as its factorization.

2215406021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 2215406021 is about 47068.0998235535. The cubic root of 2215406021 is about 1303.6202876270.

The spelling of 2215406021 in words is "two billion, two hundred fifteen million, four hundred six thousand, twenty-one".