1666497879274 has 4 divisors (see below), whose sum is σ = 2499746818914. Its totient is φ = 833248939636.

The previous prime is 1666497879247. The next prime is 1666497879287. The reversal of 1666497879274 is 4729787946661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1534142346025 + 132355533249 = 1238605^2 + 363807^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1666497879274.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416624469817 + ... + 416624469820.

Almost surely, 2^{1666497879274} is an apocalyptic number.

1666497879274 is a deficient number, since it is larger than the sum of its proper divisors (833248939640).

1666497879274 is an equidigital number, since it uses as much as digits as its factorization.

1666497879274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833248939639.

The product of its digits is 1536288768, while the sum is 76.

The spelling of 1666497879274 in words is "one trillion, six hundred sixty-six billion, four hundred ninety-seven million, eight hundred seventy-nine thousand, two hundred seventy-four".