3531561640 has 64 divisors (see below), whose sum is σ = 8444250000. Its totient is φ = 1324658688.

The previous prime is 3531561629. The next prime is 3531561653. The reversal of 3531561640 is 461651353.

It can be written as a sum of positive squares in 8 ways, for example, as 1664803204 + 1866758436 = 40802^2 + 43206^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 3531561596 and 3531561605.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 178986 + ... + 197734.

Almost surely, 2^3531561640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3531561640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4222125000).

3531561640 is an abundant number, since it is smaller than the sum of its proper divisors (4912688360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3531561640 is a wasteful number, since it uses less digits than its factorization.

3531561640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19054 (or 19050 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 3531561640 is about 59426.9437208410. The cubic root of 3531561640 is about 1522.8446326406.

The spelling of 3531561640 in words is "three billion, five hundred thirty-one million, five hundred sixty-one thousand, six hundred forty".