72415421 has 4 divisors (see below), whose sum is σ = 77985852. Its totient is φ = 66844992.

The previous prime is 72415373. The next prime is 72415423. The reversal of 72415421 is 12451427.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14822500 + 57592921 = 3850^2 + 7589^2 .

It is a cyclic number.

It is not a de Polignac number, because 72415421 - 2²² = 68221117 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 (72415423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2785196 + ... + 2785221.

It is an arithmetic number, because the mean of its divisors is an integer number (19496463).

Almost surely, 2^72415421 is an apocalyptic number.

It is an amenable number.

72415421 is a deficient number, since it is larger than the sum of its proper divisors (5570431).

72415421 is a wasteful number, since it uses less digits than its factorization.

72415421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5570430.

The product of its digits is 2240, while the sum is 26.

The square root of 72415421 is about 8509.7250836910. The cubic root of 72415421 is about 416.8153330474.

Adding to 72415421 its reverse (12451427), we get a palindrome (84866848).

The spelling of 72415421 in words is "seventy-two million, four hundred fifteen thousand, four hundred twenty-one".