1265210123 has 4 divisors (see below), whose sum is σ = 1266922920. Its totient is φ = 1263497328.

The previous prime is 1265210119. The next prime is 1265210137. The reversal of 1265210123 is 3210125621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1265210123 - 2² = 1265210119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1265210143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 855290 + ... + 856767.

It is an arithmetic number, because the mean of its divisors is an integer number (316730730).

Almost surely, 2^1265210123 is an apocalyptic number.

1265210123 is a deficient number, since it is larger than the sum of its proper divisors (1712797).

1265210123 is an equidigital number, since it uses as much as digits as its factorization.

1265210123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1712796.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 1265210123 is about 35569.7922822161. The cubic root of 1265210123 is about 1081.5689710011.

Adding to 1265210123 its reverse (3210125621), we get a palindrome (4475335744).

The spelling of 1265210123 in words is "one billion, two hundred sixty-five million, two hundred ten thousand, one hundred twenty-three".