1978624129 has 4 divisors (see below), whose sum is σ = 1997834176. Its totient is φ = 1959414084.

The previous prime is 1978624111. The next prime is 1978624133. The reversal of 1978624129 is 9214268791.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1978624129 - 2⁵ = 1978624097 is a prime.

It is a super-2 number, since 2×1978624129² = 7829906887722017282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978624159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9604869 + ... + 9605074.

It is an arithmetic number, because the mean of its divisors is an integer number (499458544).

Almost surely, 2^1978624129 is an apocalyptic number.

It is an amenable number.

1978624129 is a deficient number, since it is larger than the sum of its proper divisors (19210047).

1978624129 is a wasteful number, since it uses less digits than its factorization.

1978624129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19210046.

The product of its digits is 435456, while the sum is 49.

The square root of 1978624129 is about 44481.7280352281. The cubic root of 1978624129 is about 1255.4163111479.

The spelling of 1978624129 in words is "one billion, nine hundred seventy-eight million, six hundred twenty-four thousand, one hundred twenty-nine".