1261539154560 has 128 divisors (see below), whose sum is σ = 4021657632000. Its totient is φ = 336368480256.

The previous prime is 1261539154559. The next prime is 1261539154607. The reversal of 1261539154560 is 654519351621.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17256966 + ... + 17329914.

It is an arithmetic number, because the mean of its divisors is an integer number (31419200250).

Almost surely, 2^{1261539154560} is an apocalyptic number.

1261539154560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261539154560 is an abundant number, since it is smaller than the sum of its proper divisors (2760118477440).

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

1261539154560 is an equidigital number, since it uses as much as digits as its factorization.

1261539154560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81978 (or 81966 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 48.

The spelling of 1261539154560 in words is "one trillion, two hundred sixty-one billion, five hundred thirty-nine million, one hundred fifty-four thousand, five hundred sixty".