65217021 has 8 divisors (see below), whose sum is σ = 87459360. Its totient is φ = 43226352.

The previous prime is 65216999. The next prime is 65217023. The reversal of 65217021 is 12071256.

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

It is not a de Polignac number, because 65217021 - 2¹⁷ = 65085949 is a prime.

It is a super-2 number, since 2×65217021² = 8506519656228882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 65216982 and 65217000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65217023) 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, 62311 + ... + 63348.

It is an arithmetic number, because the mean of its divisors is an integer number (10932420).

Almost surely, 2^65217021 is an apocalyptic number.

It is an amenable number.

65217021 is a deficient number, since it is larger than the sum of its proper divisors (22242339).

65217021 is a wasteful number, since it uses less digits than its factorization.

65217021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125835.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 65217021 is about 8075.7056038466. The cubic root of 65217021 is about 402.5195566800.

Adding to 65217021 its reverse (12071256), we get a palindrome (77288277).

The spelling of 65217021 in words is "sixty-five million, two hundred seventeen thousand, twenty-one".