78820511 has 8 divisors (see below), whose sum is σ = 98269824. Its totient is φ = 61418520.

The previous prime is 78820477. The next prime is 78820537. The reversal of 78820511 is 11502887.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 78820511 - 2¹⁸ = 78558367 is a prime.

It is a super-2 number, since 2×78820511² = 12425345908602242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78820541) 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, 511745 + ... + 511898.

It is an arithmetic number, because the mean of its divisors is an integer number (12283728).

Almost surely, 2^78820511 is an apocalyptic number.

78820511 is a deficient number, since it is larger than the sum of its proper divisors (19449313).

78820511 is a wasteful number, since it uses less digits than its factorization.

78820511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1023661.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 78820511 is about 8878.0916305251. The cubic root of 78820511 is about 428.7588348272.

The spelling of 78820511 in words is "seventy-eight million, eight hundred twenty thousand, five hundred eleven".