3947747640 has 32 divisors (see below), whose sum is σ = 11843243280. Its totient is φ = 1052732672.

The previous prime is 3947747627. The next prime is 3947747647. The reversal of 3947747640 is 467477493.

It is a super-2 number, since 2×3947747640² = 31169422858251139200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3947747647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16448829 + ... + 16449068.

Almost surely, 2^3947747640 is an apocalyptic number.

3947747640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3947747640 is an abundant number, since it is smaller than the sum of its proper divisors (7895495640).

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

3947747640 is a wasteful number, since it uses less digits than its factorization.

3947747640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32897911 (or 32897907 counting only the distinct ones).

The product of its (nonzero) digits is 3556224, while the sum is 51.

The square root of 3947747640 is about 62831.1040807019. The cubic root of 3947747640 is about 1580.4586127971.

The spelling of 3947747640 in words is "three billion, nine hundred forty-seven million, seven hundred forty-seven thousand, six hundred forty".