78511949 has 16 divisors (see below), whose sum is σ = 85155840. Its totient is φ = 72196080.

The previous prime is 78511931. The next prime is 78511957. The reversal of 78511949 is 94911587.

It is a de Polignac number, because none of the positive numbers 2^k-78511949 is a prime.

It is a super-2 number, since 2×78511949² = 12328252271557202, 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 (78511649) 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, 63164 + ... + 64394.

It is an arithmetic number, because the mean of its divisors is an integer number (5322240).

Almost surely, 2^78511949 is an apocalyptic number.

It is an amenable number.

78511949 is a deficient number, since it is larger than the sum of its proper divisors (6643891).

78511949 is a wasteful number, since it uses less digits than its factorization.

78511949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360.

The product of its digits is 90720, while the sum is 44.

The square root of 78511949 is about 8860.6968687570. The cubic root of 78511949 is about 428.1986096743.

The spelling of 78511949 in words is "seventy-eight million, five hundred eleven thousand, nine hundred forty-nine".