3561981 has 8 divisors (see below), whose sum is σ = 4762560. Its totient is φ = 2368032.

The previous prime is 3561977. The next prime is 3561997. The reversal of 3561981 is 1891653.

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

It is not a de Polignac number, because 3561981 - 2² = 3561977 is a prime.

It is a super-2 number, since 2×3561981² = 25375417288722, which contains 22 as substring.

3561981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3561581) 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, 225 + ... + 2678.

It is an arithmetic number, because the mean of its divisors is an integer number (595320).

Almost surely, 2^3561981 is an apocalyptic number.

It is an amenable number.

3561981 is a deficient number, since it is larger than the sum of its proper divisors (1200579).

3561981 is a wasteful number, since it uses less digits than its factorization.

3561981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3315.

The product of its digits is 6480, while the sum is 33.

The square root of 3561981 is about 1887.3211173513. The cubic root of 3561981 is about 152.7204515674.

The spelling of 3561981 in words is "three million, five hundred sixty-one thousand, nine hundred eighty-one".