551391620400 has 720 divisors, whose sum is σ = 2145783687840. Its totient is φ = 130299494400.

The previous prime is 551391620389. The next prime is 551391620411. The reversal of 551391620400 is 4026193155.

551391620400 is a `hidden beast` number, since 551 + 3 + 9 + 1 + 62 + 0 + 40 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (551391620389) and next prime (551391620411).

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 201163030 + ... + 201165770.

It is an arithmetic number, because the mean of its divisors is an integer number (2980255122).

Almost surely, 2^551391620400 is an apocalyptic number.

551391620400 is a gapful number since it is divisible by the number (50) 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 551391620400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1072891843920).

551391620400 is an abundant number, since it is smaller than the sum of its proper divisors (1594392067440).

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

551391620400 is a wasteful number, since it uses less digits than its factorization.

551391620400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2974 (or 2960 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 551391620400 in words is "five hundred fifty-one billion, three hundred ninety-one million, six hundred twenty thousand, four hundred".