6656942040 has 384 divisors, whose sum is σ = 24293545920. Its totient is φ = 1453670400.

The previous prime is 6656942029. The next prime is 6656942041. The reversal of 6656942040 is 402496566.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 6656941983 and 6656942001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6656942041) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12776980 + ... + 12777500.

Almost surely, 2^6656942040 is an apocalyptic number.

6656942040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6656942040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12146772960).

6656942040 is an abundant number, since it is smaller than the sum of its proper divisors (17636603880).

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

6656942040 is a wasteful number, since it uses less digits than its factorization.

6656942040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643 (or 632 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 6656942040 is about 81590.0854270910. The cubic root of 6656942040 is about 1881.1564900339.

The spelling of 6656942040 in words is "six billion, six hundred fifty-six million, nine hundred forty-two thousand, forty".