400621878720 has 1120 divisors, whose sum is σ = 1682472591360. Its totient is φ = 88594145280.

The previous prime is 400621878707. The next prime is 400621878721. The reversal of 400621878720 is 27878126004.

400621878720 is a `hidden beast` number, since 400 + 6 + 218 + 7 + 8 + 7 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1120).

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 (400621878721) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 929516905 + ... + 929517335.

Almost surely, 2^400621878720 is an apocalyptic number.

400621878720 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 400621878720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (841236295680).

400621878720 is an abundant number, since it is smaller than the sum of its proper divisors (1281850712640).

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

400621878720 is a wasteful number, since it uses less digits than its factorization.

400621878720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623 (or 604 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The spelling of 400621878720 in words is "four hundred billion, six hundred twenty-one million, eight hundred seventy-eight thousand, seven hundred twenty".