78398749 has 8 divisors (see below), whose sum is σ = 92104992. Its totient is φ = 65789040.

The previous prime is 78398741. The next prime is 78398767. The reversal of 78398749 is 94789387.

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 78398749 - 2³ = 78398741 is a prime.

It is a super-2 number, since 2×78398749² = 12292727689530002, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78398749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78398741) 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, 273979 + ... + 274264.

It is an arithmetic number, because the mean of its divisors is an integer number (11513124).

Almost surely, 2^78398749 is an apocalyptic number.

It is an amenable number.

78398749 is a deficient number, since it is larger than the sum of its proper divisors (13706243).

78398749 is a wasteful number, since it uses less digits than its factorization.

78398749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548267.

The product of its digits is 3048192, while the sum is 55.

The square root of 78398749 is about 8854.3068051655. The cubic root of 78398749 is about 427.9927157610.

The spelling of 78398749 in words is "seventy-eight million, three hundred ninety-eight thousand, seven hundred forty-nine".