64206421 has 4 divisors (see below), whose sum is σ = 64325644. Its totient is φ = 64087200.

The previous prime is 64206419. The next prime is 64206427. The reversal of 64206421 is 12460246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12460246 = 2 ⋅6230123.

It can be written as a sum of positive squares in 2 ways, for example, as 16112196 + 48094225 = 4014^2 + 6935^2 .

It is a cyclic number.

It is not a de Polignac number, because 64206421 - 2¹ = 64206419 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 (64206427) 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, 58800 + ... + 59881.

It is an arithmetic number, because the mean of its divisors is an integer number (16081411).

Almost surely, 2^64206421 is an apocalyptic number.

It is an amenable number.

64206421 is a deficient number, since it is larger than the sum of its proper divisors (119223).

64206421 is a wasteful number, since it uses less digits than its factorization.

64206421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119222.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 64206421 is about 8012.8909265009. The cubic root of 64206421 is about 400.4295822326.

Adding to 64206421 its reverse (12460246), we get a palindrome (76666667).

The spelling of 64206421 in words is "sixty-four million, two hundred six thousand, four hundred twenty-one".