1231867551550 has 48 divisors (see below), whose sum is σ = 2426731241760. Its totient is φ = 463632527360.

The previous prime is 1231867551539. The next prime is 1231867551571. The reversal of 1231867551550 is 551557681321.

It is a junction number, because it is equal to n+sod(n) for n = 1231867551494 and 1231867551503.

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, 2874111 + ... + 3274789.

It is an arithmetic number, because the mean of its divisors is an integer number (50556900870).

Almost surely, 2^{1231867551550} is an apocalyptic number.

1231867551550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1231867551550 is a deficient number, since it is larger than the sum of its proper divisors (1194863690210).

1231867551550 is a wasteful number, since it uses less digits than its factorization.

1231867551550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404325 (or 404320 counting only the distinct ones).

The product of its (nonzero) digits is 1260000, while the sum is 49.

The spelling of 1231867551550 in words is "one trillion, two hundred thirty-one billion, eight hundred sixty-seven million, five hundred fifty-one thousand, five hundred fifty".