1261533373440 has 704 divisors, whose sum is σ = 4232137455360. Its totient is φ = 320510361600.

The previous prime is 1261533373439. The next prime is 1261533373459. The reversal of 1261533373440 is 443733351621.

It is a junction number, because it is equal to n+sod(n) for n = 1261533373392 and 1261533373401.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5508879246 + ... + 5508879474.

Almost surely, 2^{1261533373440} is an apocalyptic number.

1261533373440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261533373440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2116068727680).

1261533373440 is an abundant number, since it is smaller than the sum of its proper divisors (2970604081920).

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

1261533373440 is a wasteful number, since it uses less digits than its factorization.

1261533373440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 460 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 42.

The spelling of 1261533373440 in words is "one trillion, two hundred sixty-one billion, five hundred thirty-three million, three hundred seventy-three thousand, four hundred forty".