65421215 has 4 divisors (see below), whose sum is σ = 78505464. Its totient is φ = 52336968.

The previous prime is 65421211. The next prime is 65421221. The reversal of 65421215 is 51212456.

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

It is a cyclic number.

It is not a de Polignac number, because 65421215 - 2² = 65421211 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65421211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6542117 + ... + 6542126.

It is an arithmetic number, because the mean of its divisors is an integer number (19626366).

Almost surely, 2^65421215 is an apocalyptic number.

65421215 is a deficient number, since it is larger than the sum of its proper divisors (13084249).

65421215 is a wasteful number, since it uses less digits than its factorization.

65421215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13084248.

The product of its digits is 2400, while the sum is 26.

The square root of 65421215 is about 8088.3382100404. The cubic root of 65421215 is about 402.9392142330.

The spelling of 65421215 in words is "sixty-five million, four hundred twenty-one thousand, two hundred fifteen".