1226561765 has 16 divisors (see below), whose sum is σ = 1729195776. Its totient is φ = 823425600.

The previous prime is 1226561759. The next prime is 1226561767. The reversal of 1226561765 is 5671656221.

1226561765 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1226561765 - 2²⁰ = 1225513189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1226561767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 857021 + ... + 858450.

It is an arithmetic number, because the mean of its divisors is an integer number (108074736).

Almost surely, 2^1226561765 is an apocalyptic number.

It is an amenable number.

1226561765 is a deficient number, since it is larger than the sum of its proper divisors (502634011).

1226561765 is a wasteful number, since it uses less digits than its factorization.

1226561765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715500.

The product of its digits is 151200, while the sum is 41.

The square root of 1226561765 is about 35022.3038219932. The cubic root of 1226561765 is about 1070.4420001150.

It can be divided in two parts, 122656 and 1765, that added together give a palindrome (124421).

The spelling of 1226561765 in words is "one billion, two hundred twenty-six million, five hundred sixty-one thousand, seven hundred sixty-five".