1861936129 has 2 divisors, whose sum is σ = 1861936130. Its totient is φ = 1861936128.

The previous prime is 1861936093. The next prime is 1861936133. The reversal of 1861936129 is 9216391681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1157564529 + 704371600 = 34023^2 + 26540^2 .

It is a cyclic number.

It is not a de Polignac number, because 1861936129 - 2⁹ = 1861935617 is a prime.

It is a super-2 number, since 2×1861936129² = 6933612296951009282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1861936199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930968064 + 930968065.

It is an arithmetic number, because the mean of its divisors is an integer number (930968065).

Almost surely, 2^1861936129 is an apocalyptic number.

It is an amenable number.

1861936129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861936129 is an equidigital number, since it uses as much as digits as its factorization.

1861936129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 46.

The square root of 1861936129 is about 43150.1579255511. The cubic root of 1861936129 is about 1230.2355133222.

The spelling of 1861936129 in words is "one billion, eight hundred sixty-one million, nine hundred thirty-six thousand, one hundred twenty-nine".