1561965 has 16 divisors (see below), whose sum is σ = 2526336. Its totient is φ = 824000.

The previous prime is 1561919. The next prime is 1562051. The reversal of 1561965 is 5691651.

It is not a de Polignac number, because 1561965 - 2⁹ = 1561453 is a prime.

It is a super-2 number, since 2×1561965² = 4879469322450, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

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, 1000 + ... + 2030.

It is an arithmetic number, because the mean of its divisors is an integer number (157896).

2^1561965 is an apocalyptic number.

1561965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1561965 is a deficient number, since it is larger than the sum of its proper divisors (964371).

1561965 is a wasteful number, since it uses less digits than its factorization.

1561965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140.

The product of its digits is 8100, while the sum is 33.

The square root of 1561965 is about 1249.7859816785. The cubic root of 1561965 is about 116.0264753283.

The spelling of 1561965 in words is "one million, five hundred sixty-one thousand, nine hundred sixty-five".