643477550 has 24 divisors (see below), whose sum is σ = 1197626472. Its totient is φ = 257228000.

The previous prime is 643477529. The next prime is 643477559. The reversal of 643477550 is 55774346.

It is a junction number, because it is equal to n+sod(n) for n = 643477498 and 643477507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643477559) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104045 + ... + 110055.

It is an arithmetic number, because the mean of its divisors is an integer number (49901103).

Almost surely, 2^643477550 is an apocalyptic number.

643477550 is a deficient number, since it is larger than the sum of its proper divisors (554148922).

643477550 is a wasteful number, since it uses less digits than its factorization.

643477550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8164 (or 8159 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 41.

The square root of 643477550 is about 25366.8592852958. The cubic root of 643477550 is about 863.3319229300.

The spelling of 643477550 in words is "six hundred forty-three million, four hundred seventy-seven thousand, five hundred fifty".