64145021 has 4 divisors (see below), whose sum is σ = 65048544. Its totient is φ = 63241500.

The previous prime is 64145017. The next prime is 64145023. The reversal of 64145021 is 12054146.

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 a cyclic number.

It is not a de Polignac number, because 64145021 - 2² = 64145017 is a prime.

It is a super-2 number, since 2×64145021² = 8229167438180882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64145023) 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, 451655 + ... + 451796.

It is an arithmetic number, because the mean of its divisors is an integer number (16262136).

Almost surely, 2^64145021 is an apocalyptic number.

It is an amenable number.

64145021 is a deficient number, since it is larger than the sum of its proper divisors (903523).

64145021 is an equidigital number, since it uses as much as digits as its factorization.

64145021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903522.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 64145021 is about 8009.0586837655. The cubic root of 64145021 is about 400.3018991682.

Adding to 64145021 its reverse (12054146), we get a palindrome (76199167).

The spelling of 64145021 in words is "sixty-four million, one hundred forty-five thousand, twenty-one".