3509985781 has 8 divisors (see below), whose sum is σ = 3565409984. Its totient is φ = 3454760160.

The previous prime is 3509985737. The next prime is 3509985887. The reversal of 3509985781 is 1875899053.

3509985781 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 3509985781 - 2¹¹ = 3509983733 is a prime.

It is a super-2 number, since 2×3509985781² = 24640000365644359922, 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 (3509985701) 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, 13815 + ... + 84916.

It is an arithmetic number, because the mean of its divisors is an integer number (445676248).

Almost surely, 2^3509985781 is an apocalyptic number.

It is an amenable number.

3509985781 is a deficient number, since it is larger than the sum of its proper divisors (55424203).

3509985781 is an equidigital number, since it uses as much as digits as its factorization.

3509985781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99291.

The product of its (nonzero) digits is 2721600, while the sum is 55.

The square root of 3509985781 is about 59245.1329730975. The cubic root of 3509985781 is about 1519.7370535746.

The spelling of 3509985781 in words is "three billion, five hundred nine million, nine hundred eighty-five thousand, seven hundred eighty-one".