1662772661 has 4 divisors (see below), whose sum is σ = 1813933824. Its totient is φ = 1511611500.

The previous prime is 1662772621. The next prime is 1662772679.

1662772661 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1662772661 - 2⁶ = 1662772597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1662772621) 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, 75580565 + ... + 75580586.

It is an arithmetic number, because the mean of its divisors is an integer number (453483456).

Almost surely, 2^1662772661 is an apocalyptic number.

1662772661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1662772661 is a deficient number, since it is larger than the sum of its proper divisors (151161163).

1662772661 is a wasteful number, since it uses less digits than its factorization.

1662772661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151161162.

The product of its digits is 254016, while the sum is 44.

The square root of 1662772661 is about 40777.1095223779. The cubic root of 1662772661 is about 1184.7070105940.

The spelling of 1662772661 in words is "one billion, six hundred sixty-two million, seven hundred seventy-two thousand, six hundred sixty-one".