309978403875 has 400 divisors, whose sum is σ = 692830442304. Its totient is φ = 137803680000.

The previous prime is 309978403859. The next prime is 309978403877. The reversal of 309978403875 is 578304879903.

309978403875 is a `hidden beast` number, since 3 + 0 + 99 + 78 + 403 + 8 + 75 = 666.

It is not a de Polignac number, because 309978403875 - 2⁴ = 309978403859 is a prime.

It is a super-2 number, since 2×309978403875² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (309978403877) by changing a digit.

It is a polite number, since it can be written in 399 ways as a sum of consecutive naturals, for example, 996714970 + ... + 996715280.

Almost surely, 2^309978403875 is an apocalyptic number.

309978403875 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

309978403875 is an abundant number, since it is smaller than the sum of its proper divisors (382852038429).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

309978403875 is an frugal number, since it uses more digits than its factorization.

309978403875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 45722880, while the sum is 63.

The spelling of 309978403875 in words is "three hundred nine billion, nine hundred seventy-eight million, four hundred three thousand, eight hundred seventy-five".