78390551672 has 8 divisors (see below), whose sum is σ = 146982284400. Its totient is φ = 39195275832.

The previous prime is 78390551669. The next prime is 78390551699. The reversal of 78390551672 is 27615509387.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×78390551672² (a number of 23 digits) contains 22 as substring.

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, 4899409472 + ... + 4899409487.

It is an arithmetic number, because the mean of its divisors is an integer number (18372785550).

Almost surely, 2^78390551672 is an apocalyptic number.

It is an amenable number.

78390551672 is a deficient number, since it is larger than the sum of its proper divisors (68591732728).

78390551672 is a wasteful number, since it uses less digits than its factorization.

78390551672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9798818965 (or 9798818961 counting only the distinct ones).

The product of its (nonzero) digits is 3175200, while the sum is 53.

The spelling of 78390551672 in words is "seventy-eight billion, three hundred ninety million, five hundred fifty-one thousand, six hundred seventy-two".