65661020 has 12 divisors (see below), whose sum is σ = 137888184. Its totient is φ = 26264400.

The previous prime is 65660981. The next prime is 65661047. The reversal of 65661020 is 2016656.

It is a super-2 number, since 2×65661020² = 8622739094880800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1641506 + ... + 1641545.

It is an arithmetic number, because the mean of its divisors is an integer number (11490682).

Almost surely, 2^65661020 is an apocalyptic number.

It is an amenable number.

65661020 is an abundant number, since it is smaller than the sum of its proper divisors (72227164).

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

65661020 is a wasteful number, since it uses less digits than its factorization.

65661020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3283060 (or 3283058 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 65661020 is about 8103.1487706940. The cubic root of 65661020 is about 403.4309457224.

Adding to 65661020 its reverse (2016656), we get a palindrome (67677676).

The spelling of 65661020 in words is "sixty-five million, six hundred sixty-one thousand, twenty".