1261761958 has 4 divisors (see below), whose sum is σ = 1892642940. Its totient is φ = 630880978.

The previous prime is 1261761911. The next prime is 1261761959. The reversal of 1261761958 is 8591671621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8591671621 = 13 ⋅660897817.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261761959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315440488 + ... + 315440491.

It is an arithmetic number, because the mean of its divisors is an integer number (473160735).

Almost surely, 2^1261761958 is an apocalyptic number.

1261761958 is a deficient number, since it is larger than the sum of its proper divisors (630880982).

1261761958 is an equidigital number, since it uses as much as digits as its factorization.

1261761958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630880981.

The product of its digits is 181440, while the sum is 46.

The square root of 1261761958 is about 35521.2887998169. The cubic root of 1261761958 is about 1080.5855186966.

The spelling of 1261761958 in words is "one billion, two hundred sixty-one million, seven hundred sixty-one thousand, nine hundred fifty-eight".