1051661565 has 24 divisors (see below), whose sum is σ = 1930109688. Its totient is φ = 527892480.

The previous prime is 1051661561. The next prime is 1051661623. The reversal of 1051661565 is 5651661501.

It can be written as a sum of positive squares in 4 ways, for example, as 85322169 + 966339396 = 9237^2 + 31086^2 .

It is not a de Polignac number, because 1051661565 - 2² = 1051661561 is a prime.

It is a super-2 number, since 2×1051661565² = 2211984094596498450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1051661561) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 686596 + ... + 688125.

It is an arithmetic number, because the mean of its divisors is an integer number (80421237).

Almost surely, 2^1051661565 is an apocalyptic number.

1051661565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1051661565 is a deficient number, since it is larger than the sum of its proper divisors (878448123).

1051661565 is a wasteful number, since it uses less digits than its factorization.

1051661565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1374749 (or 1374746 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 36.

The square root of 1051661565 is about 32429.3318617575. The cubic root of 1051661565 is about 1016.9322039833.

The spelling of 1051661565 in words is "one billion, fifty-one million, six hundred sixty-one thousand, five hundred sixty-five".