6521552640 has 108 divisors (see below), whose sum is σ = 22563932664. Its totient is φ = 1739077632.

The previous prime is 6521552629. The next prime is 6521552651. The reversal of 6521552640 is 462551256.

6521552640 is a `hidden beast` number, since 6 + 5 + 2 + 1 + 5 + 5 + 2 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (6521552629) and next prime (6521552651).

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

It is a junction number, because it is equal to n+sod(n) for n = 6521552595 and 6521552604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 271534 + ... + 294573.

Almost surely, 2^6521552640 is an apocalyptic number.

6521552640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6521552640 is an abundant number, since it is smaller than the sum of its proper divisors (16042380024).

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

6521552640 is a wasteful number, since it uses less digits than its factorization.

6521552640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566134 (or 566117 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The square root of 6521552640 is about 80756.1306651080. The cubic root of 6521552640 is about 1868.3160071070.

It can be divided in two parts, 65215 and 52640, that added together give a triangular number (117855 = T₄₈₅).

The spelling of 6521552640 in words is "six billion, five hundred twenty-one million, five hundred fifty-two thousand, six hundred forty".