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4921 = 71937

4921 has 8 divisors (see below), whose sum is σ = 6080. Its totient is φ = 3888.

The previous prime is 4919. The next prime is 4931. The reversal of 4921 is 1294.

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

It is a 5-Lehmer number, since φ(4921) divides (4921-1)5.

It is a cyclic number.

It is not a de Polignac number, because 4921 - 21 = 4919 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a plaindrome in base 9 and base 16.

It is a junction number, because it is equal to n+sod(n) for n = 4895 and 4904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115 + ... + 151.

It is an arithmetic number, because the mean of its divisors is an integer number (760).

24921 is an apocalyptic number.

4921 is the 41-st hex number.

It is an amenable number.

4921 is a deficient number, since it is larger than the sum of its proper divisors (1159).

4921 is a wasteful number, since it uses less digits than its factorization.

4921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63.

The product of its digits is 72, while the sum is 16.

The square root of 4921 is about 70.1498396292. The cubic root of 4921 is about 17.0092222165.

The spelling of 4921 in words is "four thousand, nine hundred twenty-one".

Divisors: 1 7 19 37 133 259 703 4921