1261778100250 has 64 divisors (see below), whose sum is σ = 2425904312832. Its totient is φ = 491153544000.

The previous prime is 1261778100197. The next prime is 1261778100263. The reversal of 1261778100250 is 520018771621.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2696692 + ... + 3129808.

It is an arithmetic number, because the mean of its divisors is an integer number (37904754888).

Almost surely, 2^{1261778100250} is an apocalyptic number.

1261778100250 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1261778100250 is a deficient number, since it is larger than the sum of its proper divisors (1164126212582).

1261778100250 is a wasteful number, since it uses less digits than its factorization.

1261778100250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433448 (or 433438 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 40.

The spelling of 1261778100250 in words is "one trillion, two hundred sixty-one billion, seven hundred seventy-eight million, one hundred thousand, two hundred fifty".