78019988 has 6 divisors (see below), whose sum is σ = 136534986. Its totient is φ = 39009992.

The previous prime is 78019973. The next prime is 78020009. The reversal of 78019988 is 88991087.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 49589764 + 28430224 = 7042^2 + 5332^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9752495 + ... + 9752502.

It is an arithmetic number, because the mean of its divisors is an integer number (22755831).

Almost surely, 2^78019988 is an apocalyptic number.

It is an amenable number.

78019988 is a deficient number, since it is larger than the sum of its proper divisors (58514998).

78019988 is a wasteful number, since it uses less digits than its factorization.

78019988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19505001 (or 19504999 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 50.

The square root of 78019988 is about 8832.8923915103. The cubic root of 78019988 is about 427.3023615919.

The spelling of 78019988 in words is "seventy-eight million, nineteen thousand, nine hundred eighty-eight".