400636938240 has 2688 divisors, whose sum is σ = 1949029205760. Its totient is φ = 76441190400.

The previous prime is 400636938239. The next prime is 400636938311. The reversal of 400636938240 is 42839636004.

400636938240 is a `hidden beast` number, since 4 + 0 + 0 + 636 + 9 + 3 + 8 + 2 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2688).

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 223 ways as a sum of consecutive naturals, for example, 9771632620 + ... + 9771632660.

It is an arithmetic number, because the mean of its divisors is an integer number (725085270).

Almost surely, 2^400636938240 is an apocalyptic number.

400636938240 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 400636938240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (974514602880).

400636938240 is an abundant number, since it is smaller than the sum of its proper divisors (1548392267520).

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

400636938240 is a wasteful number, since it uses less digits than its factorization.

400636938240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 45.

The spelling of 400636938240 in words is "four hundred billion, six hundred thirty-six million, nine hundred thirty-eight thousand, two hundred forty".