1621751040 has 972 divisors, whose sum is σ = 7483658364. Its totient is φ = 322043904.

The previous prime is 1621751017. The next prime is 1621751093. The reversal of 1621751040 is 401571261.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 154554624 + 1467196416 = 12432^2 + 38304^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1621750995 and 1621751013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 95397112 + ... + 95397128.

It is an arithmetic number, because the mean of its divisors is an integer number (7699237).

Almost surely, 2^1621751040 is an apocalyptic number.

1621751040 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 1621751040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3741829182).

1621751040 is an abundant number, since it is smaller than the sum of its proper divisors (5861907324).

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

1621751040 is a wasteful number, since it uses less digits than its factorization.

1621751040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 1621751040 is about 40270.9701894553. The cubic root of 1621751040 is about 1174.8832936749.

The spelling of 1621751040 in words is "one billion, six hundred twenty-one million, seven hundred fifty-one thousand, forty".