72879809 has 4 divisors (see below), whose sum is σ = 74115120. Its totient is φ = 71644500.

The previous prime is 72879773. The next prime is 72879817. The reversal of 72879809 is 90897827.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 72879809 - 2¹² = 72875713 is a prime.

It is a super-2 number, since 2×72879809² = 10622933119752962, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72879409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 617567 + ... + 617684.

It is an arithmetic number, because the mean of its divisors is an integer number (18528780).

Almost surely, 2^72879809 is an apocalyptic number.

It is an amenable number.

72879809 is a deficient number, since it is larger than the sum of its proper divisors (1235311).

72879809 is a wasteful number, since it uses less digits than its factorization.

72879809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1235310.

The product of its (nonzero) digits is 508032, while the sum is 50.

The square root of 72879809 is about 8536.9672015301. The cubic root of 72879809 is about 417.7044242540.

The spelling of 72879809 in words is "seventy-two million, eight hundred seventy-nine thousand, eight hundred nine".