78421 has 8 divisors (see below), whose sum is σ = 95040. Its totient is φ = 63168.

The previous prime is 78401. The next prime is 78427. The reversal of 78421 is 12487.

78421 is nontrivially palindromic in base 15.

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

It is not a de Polignac number, because 78421 - 2¹³ = 70229 is a prime.

It is a super-2 number, since 2×78421² = 12299706482, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 78392 and 78401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78427) 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, 211 + ... + 448.

It is an arithmetic number, because the mean of its divisors is an integer number (11880).

2⁷⁸⁴²¹ is an apocalyptic number.

It is an amenable number.

78421 is a deficient number, since it is larger than the sum of its proper divisors (16619).

78421 is a wasteful number, since it uses less digits than its factorization.

78421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683.

The product of its digits is 448, while the sum is 22.

The square root of 78421 is about 280.0374974892. The cubic root of 78421 is about 42.8033202653.

The spelling of 78421 in words is "seventy-eight thousand, four hundred twenty-one".