1065661440 has 88 divisors (see below), whose sum is σ = 3408500640. Its totient is φ = 284172288.

The previous prime is 1065661433. The next prime is 1065661447. The reversal of 1065661440 is 441665601.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1065661433) and next prime (1065661447).

It is a super-2 number, since 2×1065661440² = 2271268609405747200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1065661447) 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, 19330 + ... + 50049.

Almost surely, 2^1065661440 is an apocalyptic number.

1065661440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1065661440 is an abundant number, since it is smaller than the sum of its proper divisors (2342839200).

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

1065661440 is an equidigital number, since it uses as much as digits as its factorization.

1065661440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69407 (or 69389 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 1065661440 is about 32644.4702821167. The cubic root of 1065661440 is about 1021.4248445311.

The spelling of 1065661440 in words is "one billion, sixty-five million, six hundred sixty-one thousand, four hundred forty".