643620151 has 4 divisors (see below), whose sum is σ = 643683672. Its totient is φ = 643556632.

The previous prime is 643620139. The next prime is 643620163. The reversal of 643620151 is 151026346.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (643620139) and next prime (643620163).

It is a cyclic number.

It is not a de Polignac number, because 643620151 - 2²³ = 635231543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643620101) 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, 12781 + ... + 38086.

It is an arithmetic number, because the mean of its divisors is an integer number (160920918).

Almost surely, 2^643620151 is an apocalyptic number.

643620151 is a deficient number, since it is larger than the sum of its proper divisors (63521).

643620151 is a wasteful number, since it uses less digits than its factorization.

643620151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63520.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 643620151 is about 25369.6699032526. The cubic root of 643620151 is about 863.3956925220.

Adding to 643620151 its reverse (151026346), we get a palindrome (794646497).

The spelling of 643620151 in words is "six hundred forty-three million, six hundred twenty thousand, one hundred fifty-one".