1666862551 has 4 divisors (see below), whose sum is σ = 1724340600. Its totient is φ = 1609384504.

The previous prime is 1666862531. The next prime is 1666862557. The reversal of 1666862551 is 1552686661.

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

It is a cyclic number.

It is not a de Polignac number, because 1666862551 - 2¹³ = 1666854359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666862557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28738981 + ... + 28739038.

It is an arithmetic number, because the mean of its divisors is an integer number (431085150).

Almost surely, 2^1666862551 is an apocalyptic number.

1666862551 is a deficient number, since it is larger than the sum of its proper divisors (57478049).

1666862551 is an equidigital number, since it uses as much as digits as its factorization.

1666862551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57478048.

The product of its digits is 518400, while the sum is 46.

The square root of 1666862551 is about 40827.2280592254. The cubic root of 1666862551 is about 1185.6775489886.

The spelling of 1666862551 in words is "one billion, six hundred sixty-six million, eight hundred sixty-two thousand, five hundred fifty-one".