491984640 has 216 divisors, whose sum is σ = 1945708128. Its totient is φ = 112435200.

The previous prime is 491984627. The next prime is 491984653. The reversal of 491984640 is 46489194.

It is an interprime number because it is at equal distance from previous prime (491984627) and next prime (491984653).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 77590 + ... + 83690.

It is an arithmetic number, because the mean of its divisors is an integer number (9007908).

Almost surely, 2^491984640 is an apocalyptic number.

491984640 is a gapful number since it is divisible by the number (40) 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 491984640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (972854064).

491984640 is an abundant number, since it is smaller than the sum of its proper divisors (1453723488).

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

491984640 is a wasteful number, since it uses less digits than its factorization.

491984640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6135 (or 6118 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 491984640 is about 22180.7267689767. The cubic root of 491984640 is about 789.4364618521.

The spelling of 491984640 in words is "four hundred ninety-one million, nine hundred eighty-four thousand, six hundred forty".