1213521233520 has 80 divisors (see below), whose sum is σ = 3767424262272. Its totient is φ = 323131818240.

The previous prime is 1213521233461. The next prime is 1213521233569. The reversal of 1213521233520 is 253321253121.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3537646 + ... + 3865485.

Almost surely, 2^{1213521233520} is an apocalyptic number.

1213521233520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213521233520 is an abundant number, since it is smaller than the sum of its proper divisors (2553903028752).

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

1213521233520 is a wasteful number, since it uses less digits than its factorization.

1213521233520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7403830 (or 7403824 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 30.

Adding to 1213521233520 its reverse (253321253121), we get a palindrome (1466842486641).

The spelling of 1213521233520 in words is "one trillion, two hundred thirteen billion, five hundred twenty-one million, two hundred thirty-three thousand, five hundred twenty".