1621860240 has 640 divisors, whose sum is σ = 6951555072. Its totient is φ = 301916160.

The previous prime is 1621860193. The next prime is 1621860241. The reversal of 1621860240 is 420681261.

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

It is a junction number, because it is equal to n+sod(n) for n = 1621860198 and 1621860207.

It is not an unprimeable number, because it can be changed into a prime (1621860241) 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, 10330242 + ... + 10330398.

Almost surely, 2^1621860240 is an apocalyptic number.

1621860240 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 1621860240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3475777536).

1621860240 is an abundant number, since it is smaller than the sum of its proper divisors (5329694832).

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

1621860240 is a wasteful number, since it uses less digits than its factorization.

1621860240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247 (or 241 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 1621860240 is about 40272.3259819941. The cubic root of 1621860240 is about 1174.9096631922.

The spelling of 1621860240 in words is "one billion, six hundred twenty-one million, eight hundred sixty thousand, two hundred forty".