1620899280 has 720 divisors, whose sum is σ = 7391419776. Its totient is φ = 309104640.

The previous prime is 1620899261. The next prime is 1620899303. The reversal of 1620899280 is 829980261.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 9369274 + ... + 9369446.

Almost surely, 2^1620899280 is an apocalyptic number.

1620899280 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 1620899280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3695709888).

1620899280 is an abundant number, since it is smaller than the sum of its proper divisors (5770520496).

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

1620899280 is a wasteful number, since it uses less digits than its factorization.

1620899280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 1620899280 is about 40260.3934407005. The cubic root of 1620899280 is about 1174.6775708037.

The spelling of 1620899280 in words is "one billion, six hundred twenty million, eight hundred ninety-nine thousand, two hundred eighty".