651623 has 4 divisors (see below), whose sum is σ = 744720. Its totient is φ = 558528.

The previous prime is 651617. The next prime is 651641. The reversal of 651623 is 326156.

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

It is a cyclic number.

It is not a de Polignac number, because 651623 - 2¹⁰ = 650599 is a prime.

It is a super-2 number, since 2×651623² = 849225068258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651683) 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, 46538 + ... + 46551.

It is an arithmetic number, because the mean of its divisors is an integer number (186180).

2⁶⁵¹⁶²³ is an apocalyptic number.

651623 is a deficient number, since it is larger than the sum of its proper divisors (93097).

651623 is an equidigital number, since it uses as much as digits as its factorization.

651623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93096.

The product of its digits is 1080, while the sum is 23.

The square root of 651623 is about 807.2316891698. The cubic root of 651623 is about 86.6959483568.

Adding to 651623 its reverse (326156), we get a palindrome (977779).

The spelling of 651623 in words is "six hundred fifty-one thousand, six hundred twenty-three".