1261172447950 has 48 divisors (see below), whose sum is σ = 2361722768640. Its totient is φ = 501046485120.

The previous prime is 1261172447903. The next prime is 1261172447963. The reversal of 1261172447950 is 597442711621.

It is a junction number, because it is equal to n+sod(n) for n = 1261172447894 and 1261172447903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8550931 + ... + 8697169.

It is an arithmetic number, because the mean of its divisors is an integer number (49202557680).

Almost surely, 2^{1261172447950} is an apocalyptic number.

1261172447950 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1261172447950 is a deficient number, since it is larger than the sum of its proper divisors (1100550320690).

1261172447950 is a wasteful number, since it uses less digits than its factorization.

1261172447950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147421 (or 147416 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 1261172447950 in words is "one trillion, two hundred sixty-one billion, one hundred seventy-two million, four hundred forty-seven thousand, nine hundred fifty".