2780064729666 has 40 divisors (see below), whose sum is σ = 7119319204800. Its totient is φ = 794304208152.

The previous prime is 2780064729649. The next prime is 2780064729683. The reversal of 2780064729666 is 6669274600872.

It is an interprime number because it is at equal distance from previous prime (2780064729649) and next prime (2780064729683).

It is a super-2 number, since 2×2780064729666² (a number of 26 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1225776966 + ... + 1225779233.

It is an arithmetic number, because the mean of its divisors is an integer number (177982980120).

Almost surely, 2^{2780064729666} is an apocalyptic number.

2780064729666 is an abundant number, since it is smaller than the sum of its proper divisors (4339254475134).

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

2780064729666 is a wasteful number, since it uses less digits than its factorization.

2780064729666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2451556220 (or 2451556211 counting only the distinct ones).

The product of its (nonzero) digits is 73156608, while the sum is 63.

The spelling of 2780064729666 in words is "two trillion, seven hundred eighty billion, sixty-four million, seven hundred twenty-nine thousand, six hundred sixty-six".