1264220265 has 64 divisors (see below), whose sum is σ = 2532280320. Its totient is φ = 523223040.

The previous prime is 1264220261. The next prime is 1264220291. The reversal of 1264220265 is 5620224621.

It is a happy number.

It is not a de Polignac number, because 1264220265 - 2² = 1264220261 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1264220261) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 294706 + ... + 298964.

It is an arithmetic number, because the mean of its divisors is an integer number (39566880).

Almost surely, 2^1264220265 is an apocalyptic number.

1264220265 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1264220265 is an abundant number, since it is smaller than the sum of its proper divisors (1268060055).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1264220265 is a wasteful number, since it uses less digits than its factorization.

1264220265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4542.

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 1264220265 is about 35555.8752529030. The cubic root of 1264220265 is about 1081.2868363050.

Adding to 1264220265 its reverse (5620224621), we get a palindrome (6884444886).

The spelling of 1264220265 in words is "one billion, two hundred sixty-four million, two hundred twenty thousand, two hundred sixty-five".