8420649840 has 360 divisors, whose sum is σ = 29960412768. Its totient is φ = 2200296960.

The previous prime is 8420649829. The next prime is 8420649841. The reversal of 8420649840 is 489460248.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8420649841) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 32017549 + ... + 32017811.

Almost surely, 2^8420649840 is an apocalyptic number.

8420649840 is a gapful number since it is divisible by the number (80) 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 8420649840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14980206384).

8420649840 is an abundant number, since it is smaller than the sum of its proper divisors (21539762928).

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

8420649840 is an equidigital number, since it uses as much as digits as its factorization.

8420649840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361 (or 334 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 8420649840 is about 91764.0988622457. The cubic root of 8420649840 is about 2034.4570983029.

The spelling of 8420649840 in words is "eight billion, four hundred twenty million, six hundred forty-nine thousand, eight hundred forty".