78124213 has 4 divisors (see below), whose sum is σ = 78147468. Its totient is φ = 78100960.

The previous prime is 78124153. The next prime is 78124217. The reversal of 78124213 is 31242187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31242187 = 61 ⋅512167.

It can be written as a sum of positive squares in 2 ways, for example, as 32182929 + 45941284 = 5673^2 + 6778^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78124213 is a prime.

It is a super-2 number, since 2×78124213² = 12206785313738738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78124217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5518 + ... + 13663.

It is an arithmetic number, because the mean of its divisors is an integer number (19536867).

Almost surely, 2^78124213 is an apocalyptic number.

It is an amenable number.

78124213 is a deficient number, since it is larger than the sum of its proper divisors (23255).

78124213 is a wasteful number, since it uses less digits than its factorization.

78124213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23254.

The product of its digits is 2688, while the sum is 28.

The square root of 78124213 is about 8838.7902452768. The cubic root of 78124213 is about 427.4925511965.

The spelling of 78124213 in words is "seventy-eight million, one hundred twenty-four thousand, two hundred thirteen".