2145516615666 has 32 divisors (see below), whose sum is σ = 4771694275200. Its totient is φ = 714590269200.

The previous prime is 2145516615661. The next prime is 2145516615719. The reversal of 2145516615666 is 6665166155412.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (2145516615661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16097910 + ... + 16230641.

It is an arithmetic number, because the mean of its divisors is an integer number (149115446100).

Almost surely, 2^{2145516615666} is an apocalyptic number.

2145516615666 is an abundant number, since it is smaller than the sum of its proper divisors (2626177659534).

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

2145516615666 is a wasteful number, since it uses less digits than its factorization.

2145516615666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32329791 (or 32329785 counting only the distinct ones).

The product of its digits is 7776000, while the sum is 54.

The spelling of 2145516615666 in words is "two trillion, one hundred forty-five billion, five hundred sixteen million, six hundred fifteen thousand, six hundred sixty-six".