1666767508425 has 18 divisors (see below), whose sum is σ = 2985365804382. Its totient is φ = 888942671040.

The previous prime is 1666767508403. The next prime is 1666767508507. The reversal of 1666767508425 is 5248057676661.

It can be written as a sum of positive squares in 3 ways, for example, as 38662963641 + 1628104544784 = 196629^2 + 1275972^2 .

It is not a de Polignac number, because 1666767508425 - 2⁶ = 1666767508361 is a prime.

It is a super-2 number, since 2×1666767508425² (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 17 ways as a sum of consecutive naturals, for example, 3703927572 + ... + 3703928021.

It is an arithmetic number, because the mean of its divisors is an integer number (165853655799).

Almost surely, 2^{1666767508425} is an apocalyptic number.

1666767508425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666767508425 is a deficient number, since it is larger than the sum of its proper divisors (1318598295957).

1666767508425 is a wasteful number, since it uses less digits than its factorization.

1666767508425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7407855609 (or 7407855601 counting only the distinct ones).

The product of its (nonzero) digits is 101606400, while the sum is 63.

The spelling of 1666767508425 in words is "one trillion, six hundred sixty-six billion, seven hundred sixty-seven million, five hundred eight thousand, four hundred twenty-five".