1265121730 has 8 divisors (see below), whose sum is σ = 2277219132. Its totient is φ = 506048688.

The previous prime is 1265121727. The next prime is 1265121733. The reversal of 1265121730 is 371215621.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1265121727) and next prime (1265121733).

It can be written as a sum of positive squares in 2 ways, for example, as 1049824801 + 215296929 = 32401^2 + 14673^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1265121733) 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, 63256077 + ... + 63256096.

Almost surely, 2^1265121730 is an apocalyptic number.

1265121730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1265121730 is a deficient number, since it is larger than the sum of its proper divisors (1012097402).

1265121730 is a wasteful number, since it uses less digits than its factorization.

1265121730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126512180.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 1265121730 is about 35568.5497314692. The cubic root of 1265121730 is about 1081.5437827337.

The spelling of 1265121730 in words is "one billion, two hundred sixty-five million, one hundred twenty-one thousand, seven hundred thirty".