644062047 has 4 divisors (see below), whose sum is σ = 858749400. Its totient is φ = 429374696.

The previous prime is 644062033. The next prime is 644062061. The reversal of 644062047 is 740260446.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (644062033) and next prime (644062061).

It is a cyclic number.

It is not a de Polignac number, because 644062047 - 2¹² = 644057951 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644061999 and 644062017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644062547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107343672 + ... + 107343677.

It is an arithmetic number, because the mean of its divisors is an integer number (214687350).

Almost surely, 2^644062047 is an apocalyptic number.

644062047 is a deficient number, since it is larger than the sum of its proper divisors (214687353).

644062047 is a wasteful number, since it uses less digits than its factorization.

644062047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214687352.

The product of its (nonzero) digits is 32256, while the sum is 33.

The square root of 644062047 is about 25378.3775486141. The cubic root of 644062047 is about 863.5932437321.

The spelling of 644062047 in words is "six hundred forty-four million, sixty-two thousand, forty-seven".