661013533 has 8 divisors (see below), whose sum is σ = 702829440. Its totient is φ = 619523520.

The previous prime is 661013519. The next prime is 661013539. The reversal of 661013533 is 335310166.

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

It is not a de Polignac number, because 661013533 - 2¹³ = 661005341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661013539) 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, 77283 + ... + 85408.

It is an arithmetic number, because the mean of its divisors is an integer number (87853680).

Almost surely, 2^661013533 is an apocalyptic number.

It is an amenable number.

661013533 is a deficient number, since it is larger than the sum of its proper divisors (41815907).

661013533 is a wasteful number, since it uses less digits than its factorization.

661013533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162947.

The product of its (nonzero) digits is 4860, while the sum is 28.

The square root of 661013533 is about 25710.1834493650. The cubic root of 661013533 is about 871.1042186479.

Adding to 661013533 its reverse (335310166), we get a palindrome (996323699).

The spelling of 661013533 in words is "six hundred sixty-one million, thirteen thousand, five hundred thirty-three".