It is a congruent number.
It is an unprimeable number.
Almost surely, 2121624332642420 is an apocalyptic number.
121624332642420 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 pseudoperfect number, because it is the sum of a subset of its proper divisors.
121624332642420 is a wasteful number, since it uses less digits than its factorization.
121624332642420 is an evil number, because the sum of its binary digits is even.
The spelling of 121624332642420 in words is "one hundred twenty-one trillion, six hundred twenty-four billion, three hundred thirty-two million, six hundred forty-two thousand, four hundred twenty".