400021020400 has 60 divisors (see below), whose sum is σ = 961430866272. Its totient is φ = 159945080320.

The previous prime is 400021020389. The next prime is 400021020401. The reversal of 400021020400 is 4020120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400021020401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 820572 + ... + 1213828.

Almost surely, 2^400021020400 is an apocalyptic number.

400021020400 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400021020400 is an abundant number, since it is smaller than the sum of its proper divisors (561409845872).

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

400021020400 is a wasteful number, since it uses less digits than its factorization.

400021020400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395818 (or 395807 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

Adding to 400021020400 its reverse (4020120004), we get a palindrome (404041140404).

The spelling of 400021020400 in words is "four hundred billion, twenty-one million, twenty thousand, four hundred".