129619661 has 2 divisors, whose sum is σ = 129619662. Its totient is φ = 129619660.

The previous prime is 129619643. The next prime is 129619703. The reversal of 129619661 is 166916921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115885225 + 13734436 = 10765^2 + 3706^2 .

It is a cyclic number.

It is not a de Polignac number, because 129619661 - 2¹⁰ = 129618637 is a prime.

It is a super-3 number, since 3×129619661³ (a number of 25 digits) contains 333 as substring.

It is equal to p_7357883 and since 129619661 and 7357883 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129619601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64809830 + 64809831.

It is an arithmetic number, because the mean of its divisors is an integer number (64809831).

Almost surely, 2^129619661 is an apocalyptic number.

It is an amenable number.

129619661 is a deficient number, since it is larger than the sum of its proper divisors (1).

129619661 is an equidigital number, since it uses as much as digits as its factorization.

129619661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 41.

The square root of 129619661 is about 11385.0630652623. The cubic root of 129619661 is about 506.0851885192.

It can be divided in two parts, 12961 and 9661, that added together give a palindrome (22622).

The spelling of 129619661 in words is "one hundred twenty-nine million, six hundred nineteen thousand, six hundred sixty-one".