75621 has 16 divisors (see below), whose sum is σ = 124544. Its totient is φ = 39744.

The previous prime is 75619. The next prime is 75629. The reversal of 75621 is 12657.

75621 = T₁₄ + T₁₅ + ... + T₇₆.

It is not a de Polignac number, because 75621 - 2¹ = 75619 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a nialpdrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135 + ... + 411.

It is an arithmetic number, because the mean of its divisors is an integer number (7784).

2⁷⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

75621 is a deficient number, since it is larger than the sum of its proper divisors (48923).

75621 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 16 representation: 75621 = (12765)₁₆.

75621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300.

The product of its digits is 420, while the sum is 21.

The square root of 75621 is about 274.9927271766. The cubic root of 75621 is about 42.2877071959.

It can be divided in two parts, 756 and 21, that multiplied together give a square (15876 = 126²).

The spelling of 75621 in words is "seventy-five thousand, six hundred twenty-one".