1555625640666 has 64 divisors (see below), whose sum is σ = 3163037299200. Its totient is φ = 509990208000.

The previous prime is 1555625640631. The next prime is 1555625640707. The reversal of 1555625640666 is 6660465265551.

It is a happy number.

It is a super-2 number, since 2×1555625640666² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59223976 + ... + 59250236.

It is an arithmetic number, because the mean of its divisors is an integer number (49422457800).

Almost surely, 2^{1555625640666} is an apocalyptic number.

1555625640666 is an abundant number, since it is smaller than the sum of its proper divisors (1607411658534).

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

1555625640666 is a wasteful number, since it uses less digits than its factorization.

1555625640666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27015.

The product of its (nonzero) digits is 38880000, while the sum is 57.

The spelling of 1555625640666 in words is "one trillion, five hundred fifty-five billion, six hundred twenty-five million, six hundred forty thousand, six hundred sixty-six".