78897949 has 16 divisors (see below), whose sum is σ = 88726960. Its totient is φ = 69672960.

The previous prime is 78897947. The next prime is 78897961. The reversal of 78897949 is 94979887.

It can be written as a sum of positive squares in 8 ways, for example, as 22752900 + 56145049 = 4770^2 + 7493^2 .

It is a cyclic number.

It is not a de Polignac number, because 78897949 - 2¹ = 78897947 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78897943) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27997 + ... + 30685.

It is an arithmetic number, because the mean of its divisors is an integer number (5545435).

Almost surely, 2^78897949 is an apocalyptic number.

It is an amenable number.

78897949 is a deficient number, since it is larger than the sum of its proper divisors (9829011).

78897949 is a wasteful number, since it uses less digits than its factorization.

78897949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2800.

The product of its digits is 9144576, while the sum is 61.

The square root of 78897949 is about 8882.4517448731. The cubic root of 78897949 is about 428.8992016719.

The spelling of 78897949 in words is "seventy-eight million, eight hundred ninety-seven thousand, nine hundred forty-nine".