621997740 has 432 divisors, whose sum is σ = 2455584768. Its totient is φ = 124540416.

The previous prime is 621997703. The next prime is 621997759. The reversal of 621997740 is 47799126.

621997740 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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

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, 4897557 + ... + 4897683.

It is an arithmetic number, because the mean of its divisors is an integer number (5684224).

Almost surely, 2^621997740 is an apocalyptic number.

621997740 is a gapful number since it is divisible by the number (60) 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 621997740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1227792384).

621997740 is an abundant number, since it is smaller than the sum of its proper divisors (1833587028).

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

621997740 is a wasteful number, since it uses less digits than its factorization.

621997740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The square root of 621997740 is about 24939.8825177666. The cubic root of 621997740 is about 853.6167640986.

The spelling of 621997740 in words is "six hundred twenty-one million, nine hundred ninety-seven thousand, seven hundred forty".