3161221813 has 2 divisors, whose sum is σ = 3161221814. Its totient is φ = 3161221812.

The previous prime is 3161221787. The next prime is 3161221891. The reversal of 3161221813 is 3181221613.

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., 3147546609 + 13675204 = 56103^2 + 3698^2 .

It is a cyclic number.

It is not a de Polignac number, because 3161221813 - 2¹³ = 3161213621 is a prime.

It is a super-3 number, since 3×3161221813³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3161221013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1580610906 + 1580610907.

It is an arithmetic number, because the mean of its divisors is an integer number (1580610907).

Almost surely, 2^3161221813 is an apocalyptic number.

It is an amenable number.

3161221813 is a deficient number, since it is larger than the sum of its proper divisors (1).

3161221813 is an equidigital number, since it uses as much as digits as its factorization.

3161221813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 3161221813 is about 56224.7437788737. The cubic root of 3161221813 is about 1467.6358891564.

The spelling of 3161221813 in words is "three billion, one hundred sixty-one million, two hundred twenty-one thousand, eight hundred thirteen".