64644442 has 4 divisors (see below), whose sum is σ = 96966666. Its totient is φ = 32322220.

The previous prime is 64644427. The next prime is 64644443. The reversal of 64644442 is 24444646.

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

It can be written as a sum of positive squares in only one way, i.e., 45010681 + 19633761 = 6709^2 + 4431^2 .

It is a junction number, because it is equal to n+sod(n) for n = 64644398 and 64644407.

It is not an unprimeable number, because it can be changed into a prime (64644443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16161109 + ... + 16161112.

Almost surely, 2^64644442 is an apocalyptic number.

64644442 is a deficient number, since it is larger than the sum of its proper divisors (32322224).

64644442 is a wasteful number, since it uses less digits than its factorization.

64644442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32322223.

The product of its digits is 73728, while the sum is 34.

The square root of 64644442 is about 8040.1767393509. The cubic root of 64644442 is about 401.3381061881.

The spelling of 64644442 in words is "sixty-four million, six hundred forty-four thousand, four hundred forty-two".