19400878125 has 72 divisors (see below), whose sum is σ = 37088454312. Its totient is φ = 9738240000.

The previous prime is 19400878099. The next prime is 19400878199. The reversal of 19400878125 is 52187800491.

It can be written as a sum of positive squares in 12 ways, for example, as 18165917961 + 1234960164 = 134781^2 + 35142^2 .

It is not a de Polignac number, because 19400878125 - 2⁶ = 19400878061 is a prime.

It is a super-2 number, since 2×19400878125² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 457837 + ... + 498413.

It is an arithmetic number, because the mean of its divisors is an integer number (515117421).

Almost surely, 2^19400878125 is an apocalyptic number.

19400878125 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19400878125 is a deficient number, since it is larger than the sum of its proper divisors (17687576187).

19400878125 is an equidigital number, since it uses as much as digits as its factorization.

19400878125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40625 (or 40602 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The spelling of 19400878125 in words is "nineteen billion, four hundred million, eight hundred seventy-eight thousand, one hundred twenty-five".