1213521240400 has 240 divisors, whose sum is σ = 3402278272000. Its totient is φ = 415783549440.

The previous prime is 1213521240397. The next prime is 1213521240419. The reversal of 1213521240400 is 40421253121.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 373045174 + ... + 373048426.

Almost surely, 2^{1213521240400} is an apocalyptic number.

1213521240400 is a gapful number since it is divisible by the number (10) 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 1213521240400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1701139136000).

1213521240400 is an abundant number, since it is smaller than the sum of its proper divisors (2188757031600).

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

1213521240400 is a wasteful number, since it uses less digits than its factorization.

1213521240400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6011 (or 5986 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 1213521240400 its reverse (40421253121), we get a palindrome (1253942493521).

The spelling of 1213521240400 in words is "one trillion, two hundred thirteen billion, five hundred twenty-one million, two hundred forty thousand, four hundred".