72378421 has 8 divisors (see below), whose sum is σ = 73359000. Its totient is φ = 71404032.

The previous prime is 72378379. The next prime is 72378431. The reversal of 72378421 is 12487327.

It can be written as a sum of positive squares in 4 ways, for example, as 6687396 + 65691025 = 2586^2 + 8105^2 .

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 72378421 - 2¹⁵ = 72345653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72378431) 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, 24955 + ... + 27703.

It is an arithmetic number, because the mean of its divisors is an integer number (9169875).

Almost surely, 2^72378421 is an apocalyptic number.

It is an amenable number.

72378421 is a deficient number, since it is larger than the sum of its proper divisors (980579).

72378421 is a wasteful number, since it uses less digits than its factorization.

72378421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3095.

The product of its digits is 18816, while the sum is 34.

The square root of 72378421 is about 8507.5508226516. The cubic root of 72378421 is about 416.7443316205.

The spelling of 72378421 in words is "seventy-two million, three hundred seventy-eight thousand, four hundred twenty-one".