21037990550400 has 1344 divisors, whose sum is σ = 80458322421120. Its totient is φ = 5429056389120.

The previous prime is 21037990550389. The next prime is 21037990550407. The reversal of 21037990550400 is 405509973012.

It is a happy number.

21037990550400 is a `hidden beast` number, since 2 + 1 + 0 + 3 + 7 + 9 + 90 + 550 + 4 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21037990550407) by changing a digit.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 19247932254 + ... + 19247933346.

It is an arithmetic number, because the mean of its divisors is an integer number (59864823230).

Almost surely, 2^{21037990550400} is an apocalyptic number.

21037990550400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21037990550400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40229161210560).

21037990550400 is an abundant number, since it is smaller than the sum of its proper divisors (59420331870720).

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

21037990550400 is a wasteful number, since it uses less digits than its factorization.

21037990550400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1395 (or 1363 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The spelling of 21037990550400 in words is "twenty-one trillion, thirty-seven billion, nine hundred ninety million, five hundred fifty thousand, four hundred".