1771206372661 has 4 divisors (see below), whose sum is σ = 1932225133824. Its totient is φ = 1610187611500.

The previous prime is 1771206372581. The next prime is 1771206372679. The reversal of 1771206372661 is 1662736021771.

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 1771206372661 - 2⁹ = 1771206372149 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 (1771206378661) 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, 80509380565 + ... + 80509380586.

It is an arithmetic number, because the mean of its divisors is an integer number (483056283456).

Almost surely, 2^{1771206372661} is an apocalyptic number.

1771206372661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1771206372661 is a deficient number, since it is larger than the sum of its proper divisors (161018761163).

1771206372661 is a wasteful number, since it uses less digits than its factorization.

1771206372661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161018761162.

The product of its (nonzero) digits is 889056, while the sum is 49.

The spelling of 1771206372661 in words is "one trillion, seven hundred seventy-one billion, two hundred six million, three hundred seventy-two thousand, six hundred sixty-one".