1090400640 has 128 divisors (see below), whose sum is σ = 3972222720. Its totient is φ = 249231360.

The previous prime is 1090400569. The next prime is 1090400659. The reversal of 1090400640 is 460040901.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1090400640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27126 + ... + 54005.

It is an arithmetic number, because the mean of its divisors is an integer number (31032990).

Almost surely, 2^1090400640 is an apocalyptic number.

1090400640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1090400640 is an abundant number, since it is smaller than the sum of its proper divisors (2881822080).

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

1090400640 is an equidigital number, since it uses as much as digits as its factorization.

1090400640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81160 (or 81148 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 1090400640 is about 33021.2149988458. The cubic root of 1090400640 is about 1029.2685415352.

The spelling of 1090400640 in words is "one billion, ninety million, four hundred thousand, six hundred forty".