37821 has 8 divisors (see below), whose sum is σ = 57664. Its totient is φ = 21600.

The previous prime is 37813. The next prime is 37831. The reversal of 37821 is 12873.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 37821 - 2³ = 37813 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 1801 = 37821 / (3 + 7 + 8 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 37821.

It is not an unprimeable number, because it can be changed into a prime (37811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 880 + ... + 921.

It is an arithmetic number, because the mean of its divisors is an integer number (7208).

2³⁷⁸²¹ is an apocalyptic number.

It is an amenable number.

37821 is a deficient number, since it is larger than the sum of its proper divisors (19843).

37821 is a wasteful number, since it uses less digits than its factorization.

37821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1811.

The product of its digits is 336, while the sum is 21.

The square root of 37821 is about 194.4762196259. The cubic root of 37821 is about 33.5668820504.

It can be divided in two parts, 37 and 821, that added together give a palindrome (858).

The spelling of 37821 in words is "thirty-seven thousand, eight hundred twenty-one".