1555501661540 has 24 divisors (see below), whose sum is σ = 3271730304192. Its totient is φ = 621214604640.

The previous prime is 1555501661521. The next prime is 1555501661603. The reversal of 1555501661540 is 451661055551.

It is a junction number, because it is equal to n+sod(n) for n = 1555501661491 and 1555501661500.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61615814 + ... + 61641053.

It is an arithmetic number, because the mean of its divisors is an integer number (136322096008).

Almost surely, 2^{1555501661540} is an apocalyptic number.

1555501661540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1555501661540 is an abundant number, since it is smaller than the sum of its proper divisors (1716228642652).

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

1555501661540 is a wasteful number, since it uses less digits than its factorization.

1555501661540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123257507 (or 123257505 counting only the distinct ones).

The product of its (nonzero) digits is 450000, while the sum is 44.

The spelling of 1555501661540 in words is "one trillion, five hundred fifty-five billion, five hundred one million, six hundred sixty-one thousand, five hundred forty".