1611331643 has 2 divisors, whose sum is σ = 1611331644. Its totient is φ = 1611331642.

The previous prime is 1611331639. The next prime is 1611331649. The reversal of 1611331643 is 3461331161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1611331643 - 2² = 1611331639 is a prime.

It is not a weakly prime, because it can be changed into another prime (1611331649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 805665821 + 805665822.

It is an arithmetic number, because the mean of its divisors is an integer number (805665822).

Almost surely, 2^1611331643 is an apocalyptic number.

1611331643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1611331643 is an equidigital number, since it uses as much as digits as its factorization.

1611331643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 29.

The square root of 1611331643 is about 40141.3956284532. The cubic root of 1611331643 is about 1172.3617628058.

The spelling of 1611331643 in words is "one billion, six hundred eleven million, three hundred thirty-one thousand, six hundred forty-three".