1661220627031 has 4 divisors (see below), whose sum is σ = 1898537859472. Its totient is φ = 1423903394592.

The previous prime is 1661220627023. The next prime is 1661220627049. The reversal of 1661220627031 is 1307260221661.

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

It is not a de Polignac number, because 1661220627031 - 2³ = 1661220627023 is a prime.

It is a super-2 number, since 2×1661220627031² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661220627431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118658616210 + ... + 118658616223.

It is an arithmetic number, because the mean of its divisors is an integer number (474634464868).

Almost surely, 2^{1661220627031} is an apocalyptic number.

1661220627031 is a deficient number, since it is larger than the sum of its proper divisors (237317232441).

1661220627031 is an equidigital number, since it uses as much as digits as its factorization.

1661220627031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237317232440.

The product of its (nonzero) digits is 36288, while the sum is 37.

Adding to 1661220627031 its reverse (1307260221661), we get a palindrome (2968480848692).

The spelling of 1661220627031 in words is "one trillion, six hundred sixty-one billion, two hundred twenty million, six hundred twenty-seven thousand, thirty-one".