64506021 has 4 divisors (see below), whose sum is σ = 86008032. Its totient is φ = 43004012.

The previous prime is 64506011. The next prime is 64506031. The reversal of 64506021 is 12060546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (64506011) and next prime (64506031).

It is a cyclic number.

It is not a de Polignac number, because 64506021 - 2⁵ = 64505989 is a prime.

It is a super-2 number, since 2×64506021² = 8322053490504882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 64505982 and 64506000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64506011) 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, 10751001 + ... + 10751006.

It is an arithmetic number, because the mean of its divisors is an integer number (21502008).

Almost surely, 2^64506021 is an apocalyptic number.

It is an amenable number.

64506021 is a deficient number, since it is larger than the sum of its proper divisors (21502011).

64506021 is a wasteful number, since it uses less digits than its factorization.

64506021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21502010.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 64506021 is about 8031.5640444436. The cubic root of 64506021 is about 401.0514441579.

Adding to 64506021 its reverse (12060546), we get a palindrome (76566567).

The spelling of 64506021 in words is "sixty-four million, five hundred six thousand, twenty-one".