2638436640 has 96 divisors (see below), whose sum is σ = 9498384000. Its totient is φ = 603070464.

The previous prime is 2638436627. The next prime is 2638436657. The reversal of 2638436640 is 466348362.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×2638436640² = 13922695806588979200, which contains 22 as substring.

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 = 2638436592 and 2638436601.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 389265 + ... + 395984.

It is an arithmetic number, because the mean of its divisors is an integer number (98941500).

Almost surely, 2^2638436640 is an apocalyptic number.

2638436640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2638436640 is an abundant number, since it is smaller than the sum of its proper divisors (6859947360).

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

2638436640 is a wasteful number, since it uses less digits than its factorization.

2638436640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785274 (or 785266 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 42.

The square root of 2638436640 is about 51365.7146353480. The cubic root of 2638436640 is about 1381.8117769996.

The spelling of 2638436640 in words is "two billion, six hundred thirty-eight million, four hundred thirty-six thousand, six hundred forty".