261373789 has 2 divisors, whose sum is σ = 261373790. Its totient is φ = 261373788.

The previous prime is 261373787. The next prime is 261373813. The reversal of 261373789 is 987373162.

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., 261307225 + 66564 = 16165^2 + 258^2 .

It is a cyclic number.

It is not a de Polignac number, because 261373789 - 2¹ = 261373787 is a prime.

Together with 261373787, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261373787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130686894 + 130686895.

It is an arithmetic number, because the mean of its divisors is an integer number (130686895).

Almost surely, 2^261373789 is an apocalyptic number.

It is an amenable number.

261373789 is a deficient number, since it is larger than the sum of its proper divisors (1).

261373789 is an equidigital number, since it uses as much as digits as its factorization.

261373789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 381024, while the sum is 46.

The square root of 261373789 is about 16167.0587615682. The cubic root of 261373789 is about 639.3725858087.

The spelling of 261373789 in words is "two hundred sixty-one million, three hundred seventy-three thousand, seven hundred eighty-nine".