1639257948 has 18 divisors (see below), whose sum is σ = 4143679904. Its totient is φ = 546419304.

The previous prime is 1639257943. The next prime is 1639257989. The reversal of 1639257948 is 8497529361.

1639257948 is a `hidden beast` number, since 1 + 63 + 9 + 2 + 579 + 4 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a junction number, because it is equal to n+sod(n) for n = 1639257894 and 1639257903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1639257943) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22767436 + ... + 22767507.

Almost surely, 2^1639257948 is an apocalyptic number.

1639257948 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1639257948 is an abundant number, since it is smaller than the sum of its proper divisors (2504421956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1639257948 is a wasteful number, since it uses less digits than its factorization.

1639257948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45534953 (or 45534948 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The square root of 1639257948 is about 40487.7505920000. The cubic root of 1639257948 is about 1179.0958188823.

The spelling of 1639257948 in words is "one billion, six hundred thirty-nine million, two hundred fifty-seven thousand, nine hundred forty-eight".