667398251520 has 3168 divisors, whose sum is σ = 3320703008640. Its totient is φ = 125597122560.

The previous prime is 667398251491. The next prime is 667398251557. The reversal of 667398251520 is 25152893766.

667398251520 is a `hidden beast` number, since 6 + 6 + 7 + 3 + 98 + 25 + 1 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (3168).

It is a super-2 number, since 2×667398251520² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 12592419814 + ... + 12592419866.

Almost surely, 2^667398251520 is an apocalyptic number.

667398251520 is a gapful number since it is divisible by the number (60) 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 667398251520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1660351504320).

667398251520 is an abundant number, since it is smaller than the sum of its proper divisors (2653304757120).

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

667398251520 is a wasteful number, since it uses less digits than its factorization.

667398251520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 54.

The spelling of 667398251520 in words is "six hundred sixty-seven billion, three hundred ninety-eight million, two hundred fifty-one thousand, five hundred twenty".