1021400120005 has 4 divisors (see below), whose sum is σ = 1225680144012. Its totient is φ = 817120096000.

The previous prime is 1021400120003. The next prime is 1021400120021. The reversal of 1021400120005 is 5000210041201.

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 583746425089 + 437653694916 = 764033^2 + 661554^2 .

It is not a de Polignac number, because 1021400120005 - 2¹ = 1021400120003 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 (1021400120003) 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, 102140011996 + ... + 102140012005.

It is an arithmetic number, because the mean of its divisors is an integer number (306420036003).

Almost surely, 2^{1021400120005} is an apocalyptic number.

It is an amenable number.

1021400120005 is a deficient number, since it is larger than the sum of its proper divisors (204280024007).

1021400120005 is an equidigital number, since it uses as much as digits as its factorization.

1021400120005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204280024006.

The product of its (nonzero) digits is 80, while the sum is 16.

Adding to 1021400120005 its reverse (5000210041201), we get a palindrome (6021610161206).

The spelling of 1021400120005 in words is "one trillion, twenty-one billion, four hundred million, one hundred twenty thousand, five".