620640433 has 4 divisors (see below), whose sum is σ = 709303360. Its totient is φ = 531977508.

The previous prime is 620640389. The next prime is 620640481. The reversal of 620640433 is 334046026.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 334046026 = 2 ⋅167023013.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-620640433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (620640133) 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, 44331453 + ... + 44331466.

It is an arithmetic number, because the mean of its divisors is an integer number (177325840).

Almost surely, 2^620640433 is an apocalyptic number.

It is an amenable number.

620640433 is a deficient number, since it is larger than the sum of its proper divisors (88662927).

620640433 is an equidigital number, since it uses as much as digits as its factorization.

620640433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88662926.

The product of its (nonzero) digits is 10368, while the sum is 28.

The square root of 620640433 is about 24912.6560807956. The cubic root of 620640433 is about 852.9953986027.

Adding to 620640433 its reverse (334046026), we get a palindrome (954686459).

The spelling of 620640433 in words is "six hundred twenty million, six hundred forty thousand, four hundred thirty-three".