1661120031 has 8 divisors (see below), whose sum is σ = 2345110704. Its totient is φ = 1042271360.

The previous prime is 1661120009. The next prime is 1661120039. The reversal of 1661120031 is 1300211661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1661120031 - 2¹³ = 1661111839 is a prime.

It is a super-2 number, since 2×1661120031² = 5518639514778881922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661120039) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16285440 + ... + 16285541.

It is an arithmetic number, because the mean of its divisors is an integer number (293138838).

Almost surely, 2^1661120031 is an apocalyptic number.

1661120031 is a deficient number, since it is larger than the sum of its proper divisors (683990673).

1661120031 is a wasteful number, since it uses less digits than its factorization.

1661120031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32571001.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 1661120031 is about 40756.8402970593. The cubic root of 1661120031 is about 1184.3143869965.

Adding to 1661120031 its reverse (1300211661), we get a palindrome (2961331692).

The spelling of 1661120031 in words is "one billion, six hundred sixty-one million, one hundred twenty thousand, thirty-one".