215720904478464 has 4536 divisors, whose sum is σ = 899674925130240. Its totient is φ = 51214851072000.

The previous prime is 215720904478451. The next prime is 215720904478477. The reversal of 215720904478464 is 464874409027512.

215720904478464 is a `hidden beast` number, since 2 + 1 + 5 + 7 + 20 + 90 + 447 + 84 + 6 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (215720904478451) and next prime (215720904478477).

It is a tau number, because it is divible by the number of its divisors (4536).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 503 ways as a sum of consecutive naturals, for example, 651724786779 + ... + 651724787109.

Almost surely, 2^{215720904478464} is an apocalyptic number.

215720904478464 is a gapful number since it is divisible by the number (24) 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 215720904478464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (449837462565120).

215720904478464 is an abundant number, since it is smaller than the sum of its proper divisors (683954020651776).

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

215720904478464 is a wasteful number, since it uses less digits than its factorization.

215720904478464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451 (or 404 counting only the distinct ones).

The product of its (nonzero) digits is 108380160, while the sum is 63.

The spelling of 215720904478464 in words is "two hundred fifteen trillion, seven hundred twenty billion, nine hundred four million, four hundred seventy-eight thousand, four hundred sixty-four".