77421 has 8 divisors (see below), whose sum is σ = 104544. Its totient is φ = 50960.

The previous prime is 77419. The next prime is 77431. The reversal of 77421 is 12477.

77421 is a nontrivial binomial coefficient, being equal to C(394, 2).

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

It is a cyclic number.

It is not a de Polignac number, because 77421 - 2¹ = 77419 is a prime.

It is a super-2 number, since 2×77421² = 11988022482, which contains 22 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77431) 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, 295 + ... + 491.

It is an arithmetic number, because the mean of its divisors is an integer number (13068).

2⁷⁷⁴²¹ is an apocalyptic number.

77421 is the 393-rd triangular number and also the 197-th hexagonal number.

It is an amenable number.

77421 is a deficient number, since it is larger than the sum of its proper divisors (27123).

77421 is a wasteful number, since it uses less digits than its factorization.

77421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331.

The product of its digits is 392, while the sum is 21.

The square root of 77421 is about 278.2462937759. The cubic root of 77421 is about 42.6206032278.

Adding to 77421 its reverse (12477), we get a palindrome (89898).

The spelling of 77421 in words is "seventy-seven thousand, four hundred twenty-one", and thus it is an iban number.