1263787780 has 24 divisors (see below), whose sum is σ = 2681318808. Its totient is φ = 500302848.

The previous prime is 1263787751. The next prime is 1263787787. The reversal of 1263787780 is 877873621.

It can be written as a sum of positive squares in 4 ways, for example, as 6801664 + 1256986116 = 2608^2 + 35454^2 .

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1263787787) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323779 + ... + 327658.

It is an arithmetic number, because the mean of its divisors is an integer number (111721617).

Almost surely, 2^1263787780 is an apocalyptic number.

1263787780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1263787780 is an abundant number, since it is smaller than the sum of its proper divisors (1417531028).

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

1263787780 is a wasteful number, since it uses less digits than its factorization.

1263787780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651543 (or 651541 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 49.

The square root of 1263787780 is about 35549.7929670483. The cubic root of 1263787780 is about 1081.1635208548.

The spelling of 1263787780 in words is "one billion, two hundred sixty-three million, seven hundred eighty-seven thousand, seven hundred eighty".