1620253051920 has 480 divisors, whose sum is σ = 5685134128128. Its totient is φ = 413199360000.

The previous prime is 1620253051889. The next prime is 1620253051943. The reversal of 1620253051920 is 291503520261.

It is a happy number.

1620253051920 is a `hidden beast` number, since 1 + 620 + 2 + 5 + 3 + 0 + 5 + 1 + 9 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 379359385 + ... + 379363655.

Almost surely, 2^{1620253051920} is an apocalyptic number.

1620253051920 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 1620253051920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2842567064064).

1620253051920 is an abundant number, since it is smaller than the sum of its proper divisors (4064881076208).

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

1620253051920 is a wasteful number, since it uses less digits than its factorization.

1620253051920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4583 (or 4574 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 1620253051920 in words is "one trillion, six hundred twenty billion, two hundred fifty-three million, fifty-one thousand, nine hundred twenty".