21428691400 has 24 divisors (see below), whose sum is σ = 49821707970. Its totient is φ = 8571476480.

The previous prime is 21428691373. The next prime is 21428691413. The reversal of 21428691400 is 419682412.

It can be written as a sum of positive squares in 3 ways, for example, as 20990793924 + 437897476 = 144882^2 + 20926^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21428691400.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 53571529 + ... + 53571928.

Almost surely, 2^21428691400 is an apocalyptic number.

21428691400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21428691400 is an abundant number, since it is smaller than the sum of its proper divisors (28393016570).

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

21428691400 is a wasteful number, since it uses less digits than its factorization.

21428691400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107143473 (or 107143464 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The spelling of 21428691400 in words is "twenty-one billion, four hundred twenty-eight million, six hundred ninety-one thousand, four hundred".