3501981 has 24 divisors (see below), whose sum is σ = 6037440. Its totient is φ = 2000376.

The previous prime is 3501961. The next prime is 3501989. The reversal of 3501981 is 1891053.

3501981 is a nontrivial binomial coefficient, being equal to C(2647, 2).

It is not a de Polignac number, because 3501981 - 2⁶ = 3501917 is a prime.

It is a super-2 number, since 2×3501981² = 24527741848722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3501989) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1 + ... + 2646.

It is an arithmetic number, because the mean of its divisors is an integer number (251560).

Almost surely, 2^3501981 is an apocalyptic number.

3501981 is the 2646-th triangular number.

It is an amenable number.

3501981 is a deficient number, since it is larger than the sum of its proper divisors (2535459).

3501981 is a wasteful number, since it uses less digits than its factorization.

3501981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2670 (or 2657 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 3501981 is about 1871.3580630120. The cubic root of 3501981 is about 151.8580883471.

The spelling of 3501981 in words is "three million, five hundred one thousand, nine hundred eighty-one".