1261172400 has 60 divisors (see below), whose sum is σ = 4039959432. Its totient is φ = 336312320.

The previous prime is 1261172383. The next prime is 1261172441. The reversal of 1261172400 is 42711621.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 524289 + ... + 526688.

Almost surely, 2^1261172400 is an apocalyptic number.

1261172400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261172400 is an abundant number, since it is smaller than the sum of its proper divisors (2778787032).

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

1261172400 is a wasteful number, since it uses less digits than its factorization.

1261172400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1050998 (or 1050987 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 1261172400 is about 35512.9891729773. The cubic root of 1261172400 is about 1080.4171913608.

The spelling of 1261172400 in words is "one billion, two hundred sixty-one million, one hundred seventy-two thousand, four hundred".