1601841981 has 8 divisors (see below), whose sum is σ = 2137791520. Its totient is φ = 1066893552.

The previous prime is 1601841973. The next prime is 1601842019. The reversal of 1601841981 is 1891481061.

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

It is not a de Polignac number, because 1601841981 - 2³ = 1601841973 is a prime.

It is a super-2 number, since 2×1601841981² = 5131795464188008722, which contains 22 as substring.

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 (1601841181) 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, 246535 + ... + 252948.

It is an arithmetic number, because the mean of its divisors is an integer number (267223940).

Almost surely, 2^1601841981 is an apocalyptic number.

It is an amenable number.

1601841981 is a deficient number, since it is larger than the sum of its proper divisors (535949539).

1601841981 is a wasteful number, since it uses less digits than its factorization.

1601841981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500555.

The product of its (nonzero) digits is 13824, while the sum is 39.

The square root of 1601841981 is about 40023.0181395656. The cubic root of 1601841981 is about 1170.0557552508.

It can be divided in two parts, 160184 and 1981, that added together give a triangular number (162165 = T₅₆₉).

The spelling of 1601841981 in words is "one billion, six hundred one million, eight hundred forty-one thousand, nine hundred eighty-one".