2156221513 has 8 divisors (see below), whose sum is σ = 2190575528. Its totient is φ = 2121997824.

The previous prime is 2156221499. The next prime is 2156221531. The reversal of 2156221513 is 3151226512.

It can be written as a sum of positive squares in 4 ways, for example, as 797045824 + 1359175689 = 28232^2 + 36867^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2156221513 - 2²¹ = 2154124361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2156221553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1045 + ... + 65677.

It is an arithmetic number, because the mean of its divisors is an integer number (273821941).

Almost surely, 2^2156221513 is an apocalyptic number.

It is an amenable number.

2156221513 is a deficient number, since it is larger than the sum of its proper divisors (34354015).

2156221513 is an equidigital number, since it uses as much as digits as its factorization.

2156221513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65163.

The product of its digits is 3600, while the sum is 28.

The square root of 2156221513 is about 46435.1323137988. The cubic root of 2156221513 is about 1291.9066237586.

The spelling of 2156221513 in words is "two billion, one hundred fifty-six million, two hundred twenty-one thousand, five hundred thirteen".