642036811 has 4 divisors (see below), whose sum is σ = 691424272. Its totient is φ = 592649352.

The previous prime is 642036781. The next prime is 642036823. The reversal of 642036811 is 118630246.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 642036811 - 2⁷ = 642036683 is a prime.

It is a super-2 number, since 2×642036811² = 824422533358099442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642036211) 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, 24693711 + ... + 24693736.

It is an arithmetic number, because the mean of its divisors is an integer number (172856068).

Almost surely, 2^642036811 is an apocalyptic number.

642036811 is a deficient number, since it is larger than the sum of its proper divisors (49387461).

642036811 is a wasteful number, since it uses less digits than its factorization.

642036811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49387460.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 642036811 is about 25338.4453153701. The cubic root of 642036811 is about 862.6871112919.

The spelling of 642036811 in words is "six hundred forty-two million, thirty-six thousand, eight hundred eleven".