1961569 has 4 divisors (see below), whose sum is σ = 1966000. Its totient is φ = 1957140.

The previous prime is 1961551. The next prime is 1961581. The reversal of 1961569 is 9651691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9651691 = 7 ⋅1378813.

It is a cyclic number.

It is not a de Polignac number, because 1961569 - 2⁵ = 1961537 is a prime.

It is a super-2 number, since 2×1961569² = 7695505883522, which contains 22 as substring.

It is a Duffinian number.

1961569 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1961549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1467 + ... + 2464.

It is an arithmetic number, because the mean of its divisors is an integer number (491500).

2^1961569 is an apocalyptic number.

It is an amenable number.

1961569 is a deficient number, since it is larger than the sum of its proper divisors (4431).

1961569 is an equidigital number, since it uses as much as digits as its factorization.

1961569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4430.

The product of its digits is 14580, while the sum is 37.

The square root of 1961569 is about 1400.5602450448. The cubic root of 1961569 is about 125.1798796889.

The spelling of 1961569 in words is "one million, nine hundred sixty-one thousand, five hundred sixty-nine".