642735569 has 16 divisors (see below), whose sum is σ = 741810048. Its totient is φ = 545501952.

The previous prime is 642735563. The next prime is 642735571. The reversal of 642735569 is 965537246.

It is a cyclic number.

It is not a de Polignac number, because 642735569 - 2¹⁶ = 642670033 is a prime.

It is a super-2 number, since 2×642735569² = 826218023315507522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (642735563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 360809 + ... + 362585.

It is an arithmetic number, because the mean of its divisors is an integer number (46363128).

Almost surely, 2^642735569 is an apocalyptic number.

It is an amenable number.

642735569 is a deficient number, since it is larger than the sum of its proper divisors (99074479).

642735569 is a wasteful number, since it uses less digits than its factorization.

642735569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2264.

The product of its digits is 1360800, while the sum is 47.

The square root of 642735569 is about 25352.2300597009. The cubic root of 642735569 is about 862.9999650898. Note that the first 4 decimals are identical.

The spelling of 642735569 in words is "six hundred forty-two million, seven hundred thirty-five thousand, five hundred sixty-nine".