1261421828 has 12 divisors (see below), whose sum is σ = 2337340572. Its totient is φ = 593610240.

The previous prime is 1261421809. The next prime is 1261421851. The reversal of 1261421828 is 8281241621.

It can be written as a sum of positive squares in 2 ways, for example, as 337383424 + 924038404 = 18368^2 + 30398^2 .

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9275093 + ... + 9275228.

It is an arithmetic number, because the mean of its divisors is an integer number (194778381).

Almost surely, 2^1261421828 is an apocalyptic number.

It is an amenable number.

1261421828 is a deficient number, since it is larger than the sum of its proper divisors (1075918744).

1261421828 is a wasteful number, since it uses less digits than its factorization.

1261421828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18550342 (or 18550340 counting only the distinct ones).

The product of its digits is 12288, while the sum is 35.

The square root of 1261421828 is about 35516.5007848465. The cubic root of 1261421828 is about 1080.4884130630.

The spelling of 1261421828 in words is "one billion, two hundred sixty-one million, four hundred twenty-one thousand, eight hundred twenty-eight".