1019978128421 has 8 divisors (see below), whose sum is σ = 1165695985344. Its totient is φ = 874261945440.

The previous prime is 1019978128399. The next prime is 1019978128423. The reversal of 1019978128421 is 1248218799101.

It is a happy number.

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 1019978128421 - 2²² = 1019973934117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1019978128423) 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, 1433801 + ... + 2023793.

It is an arithmetic number, because the mean of its divisors is an integer number (145711998168).

Almost surely, 2^{1019978128421} is an apocalyptic number.

It is an amenable number.

1019978128421 is a deficient number, since it is larger than the sum of its proper divisors (145717856923).

1019978128421 is an equidigital number, since it uses as much as digits as its factorization.

1019978128421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836971.

The product of its (nonzero) digits is 580608, while the sum is 53.

The spelling of 1019978128421 in words is "one trillion, nineteen billion, nine hundred seventy-eight million, one hundred twenty-eight thousand, four hundred twenty-one".