7621521408 has 312 divisors, whose sum is σ = 23460334560. Its totient is φ = 2378956800.

The previous prime is 7621521403. The next prime is 7621521421. The reversal of 7621521408 is 8041251267.

7621521408 is a `hidden beast` number, since 7 + 621 + 5 + 21 + 4 + 0 + 8 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (7621521403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75460558 + ... + 75460658.

It is an arithmetic number, because the mean of its divisors is an integer number (75193380).

Almost surely, 2^7621521408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7621521408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11730167280).

7621521408 is an abundant number, since it is smaller than the sum of its proper divisors (15838813152).

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

7621521408 is a wasteful number, since it uses less digits than its factorization.

7621521408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 7621521408 is about 87301.3253507643. The cubic root of 7621521408 is about 1967.9492352561.

The spelling of 7621521408 in words is "seven billion, six hundred twenty-one million, five hundred twenty-one thousand, four hundred eight".