3538921781 has 4 divisors (see below), whose sum is σ = 3539288064. Its totient is φ = 3538555500.

The previous prime is 3538921769. The next prime is 3538921787. The reversal of 3538921781 is 1871298353.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3538921781 - 2⁶ = 3538921717 is a prime.

It is a super-2 number, since 2×3538921781² = 25047934744072423922, which 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 (3538921787) 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, 168245 + ... + 188106.

It is an arithmetic number, because the mean of its divisors is an integer number (884822016).

Almost surely, 2^3538921781 is an apocalyptic number.

It is an amenable number.

3538921781 is a deficient number, since it is larger than the sum of its proper divisors (366283).

3538921781 is an equidigital number, since it uses as much as digits as its factorization.

3538921781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366282.

The product of its digits is 362880, while the sum is 47.

The square root of 3538921781 is about 59488.8374487181. The cubic root of 3538921781 is about 1523.9018206409.

The spelling of 3538921781 in words is "three billion, five hundred thirty-eight million, nine hundred twenty-one thousand, seven hundred eighty-one".