2001378112421 has 4 divisors (see below), whose sum is σ = 2001392067852. Its totient is φ = 2001364156992.

The previous prime is 2001378112417. The next prime is 2001378112429. The reversal of 2001378112421 is 1242118731002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1105252716100 + 896125396321 = 1051310^2 + 946639^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001378112421 - 2² = 2001378112417 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 (2001378112429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6760340 + ... + 7050173.

It is an arithmetic number, because the mean of its divisors is an integer number (500348016963).

Almost surely, 2^{2001378112421} is an apocalyptic number.

It is an amenable number.

2001378112421 is a deficient number, since it is larger than the sum of its proper divisors (13955431).

2001378112421 is a wasteful number, since it uses less digits than its factorization.

2001378112421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13955430.

The product of its (nonzero) digits is 5376, while the sum is 32.

The spelling of 2001378112421 in words is "two trillion, one billion, three hundred seventy-eight million, one hundred twelve thousand, four hundred twenty-one".