1661233117 has 2 divisors, whose sum is σ = 1661233118. Its totient is φ = 1661233116.

The previous prime is 1661233103. The next prime is 1661233127. The reversal of 1661233117 is 7113321661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1649903161 + 11329956 = 40619^2 + 3366^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661233117 is a prime.

It is a super-3 number, since 3×1661233117³ (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 (1661233127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830616558 + 830616559.

It is an arithmetic number, because the mean of its divisors is an integer number (830616559).

Almost surely, 2^1661233117 is an apocalyptic number.

It is an amenable number.

1661233117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661233117 is an equidigital number, since it uses as much as digits as its factorization.

1661233117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 31.

The square root of 1661233117 is about 40758.2275988542. The cubic root of 1661233117 is about 1184.3412617026.

Adding to 1661233117 its reverse (7113321661), we get a palindrome (8774554778).

It can be divided in two parts, 16612 and 33117, that added together give a square (49729 = 223²).

The spelling of 1661233117 in words is "one billion, six hundred sixty-one million, two hundred thirty-three thousand, one hundred seventeen".