644400462430 has 16 divisors (see below), whose sum is σ = 1210352173344. Its totient is φ = 246553220320.

The previous prime is 644400462341. The next prime is 644400462437. The reversal of 644400462430 is 34264004446.

It is a self number, because there is not a number n which added to its sum of digits gives 644400462430.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644400462437) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1400870341 + ... + 1400870800.

It is an arithmetic number, because the mean of its divisors is an integer number (75647010834).

Almost surely, 2^644400462430 is an apocalyptic number.

644400462430 is a deficient number, since it is larger than the sum of its proper divisors (565951710914).

644400462430 is a wasteful number, since it uses less digits than its factorization.

644400462430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2801741171.

The product of its (nonzero) digits is 221184, while the sum is 37.

Adding to 644400462430 its reverse (34264004446), we get a palindrome (678664466876).

The spelling of 644400462430 in words is "six hundred forty-four billion, four hundred million, four hundred sixty-two thousand, four hundred thirty".