1521663939840 has 1152 divisors, whose sum is σ = 5755205965824. Its totient is φ = 341380300800.

The previous prime is 1521663939797. The next prime is 1521663939847. The reversal of 1521663939840 is 489393661251.

It is a super-2 number, since 2×1521663939840² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521663939847) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7211677335 + ... + 7211677545.

It is an arithmetic number, because the mean of its divisors is an integer number (4995838512).

Almost surely, 2^{1521663939840} is an apocalyptic number.

1521663939840 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 1521663939840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2877602982912).

1521663939840 is an abundant number, since it is smaller than the sum of its proper divisors (4233542025984).

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

1521663939840 is a wasteful number, since it uses less digits than its factorization.

1521663939840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 57.

The spelling of 1521663939840 in words is "one trillion, five hundred twenty-one billion, six hundred sixty-three million, nine hundred thirty-nine thousand, eight hundred forty".