1261400004 has 36 divisors (see below), whose sum is σ = 3274719084. Its totient is φ = 409102272.

The previous prime is 1261400003. The next prime is 1261400011. The reversal of 1261400004 is 4000041621.

1261400004 is a `hidden beast` number, since 1 + 261 + 400 + 0 + 0 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 826677504 + 434722500 = 28752^2 + 20850^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×1261400004² = 3182259940182400032, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 1261400004.

It is not an unprimeable number, because it can be changed into a prime (1261400003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 472167 + ... + 474830.

It is an arithmetic number, because the mean of its divisors is an integer number (90964419).

Almost surely, 2^1261400004 is an apocalyptic number.

It is an amenable number.

1261400004 is an abundant number, since it is smaller than the sum of its proper divisors (2013319080).

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

1261400004 is a wasteful number, since it uses less digits than its factorization.

1261400004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947044 (or 947039 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1261400004 is about 35516.1935460432. The cubic root of 1261400004 is about 1080.4821818102.

Adding to 1261400004 its reverse (4000041621), we get a palindrome (5261441625).

The spelling of 1261400004 in words is "one billion, two hundred sixty-one million, four hundred thousand, four".