76720809 has 8 divisors (see below), whose sum is σ = 111593952. Its totient is φ = 46497440.

The previous prime is 76720807. The next prime is 76720811. The reversal of 76720809 is 90802767.

It is an interprime number because it is at equal distance from previous prime (76720807) and next prime (76720811).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 76720809 - 2¹ = 76720807 is a prime.

It is a super-2 number, since 2×76720809² = 11772165067228962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (76720807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1162404 + ... + 1162469.

It is an arithmetic number, because the mean of its divisors is an integer number (13949244).

Almost surely, 2^76720809 is an apocalyptic number.

It is an amenable number.

76720809 is a deficient number, since it is larger than the sum of its proper divisors (34873143).

76720809 is a wasteful number, since it uses less digits than its factorization.

76720809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2324887.

The product of its (nonzero) digits is 42336, while the sum is 39.

The square root of 76720809 is about 8759.0415571568. The cubic root of 76720809 is about 424.9172784792.

The spelling of 76720809 in words is "seventy-six million, seven hundred twenty thousand, eight hundred nine".