639770049 has 16 divisors (see below), whose sum is σ = 965692800. Its totient is φ = 418465008.

The previous prime is 639770023. The next prime is 639770081. The reversal of 639770049 is 940077936.

639770049 is a `hidden beast` number, since 639 + 7 + 7 + 0 + 0 + 4 + 9 = 666.

It is not a de Polignac number, because 639770049 - 2¹⁵ = 639737281 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 639769986 and 639770013.

It is not an unprimeable number, because it can be changed into a prime (639770149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 222109 + ... + 224970.

It is an arithmetic number, because the mean of its divisors is an integer number (60355800).

Almost surely, 2^639770049 is an apocalyptic number.

It is an amenable number.

639770049 is a deficient number, since it is larger than the sum of its proper divisors (325922751).

639770049 is a wasteful number, since it uses less digits than its factorization.

639770049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447141 (or 447135 counting only the distinct ones).

The product of its (nonzero) digits is 285768, while the sum is 45.

The square root of 639770049 is about 25293.6760673493. The cubic root of 639770049 is about 861.6706523134.

The spelling of 639770049 in words is "six hundred thirty-nine million, seven hundred seventy thousand, forty-nine".