643616454 has 16 divisors (see below), whose sum is σ = 1386250992. Its totient is φ = 198035808.

The previous prime is 643616423. The next prime is 643616461. The reversal of 643616454 is 454616346.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4125669 + ... + 4125824.

It is an arithmetic number, because the mean of its divisors is an integer number (86640687).

Almost surely, 2^643616454 is an apocalyptic number.

643616454 is an abundant number, since it is smaller than the sum of its proper divisors (742634538).

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

643616454 is a wasteful number, since it uses less digits than its factorization.

643616454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8251511.

The product of its digits is 207360, while the sum is 39.

The square root of 643616454 is about 25369.5970405523. The cubic root of 643616454 is about 863.3940393833.

The spelling of 643616454 in words is "six hundred forty-three million, six hundred sixteen thousand, four hundred fifty-four".