654401664 has 144 divisors (see below), whose sum is σ = 2190744270. Its totient is φ = 186955776.

The previous prime is 654401659. The next prime is 654401677. The reversal of 654401664 is 466104456.

It can be written as a sum of positive squares in only one way, i.e., 399680064 + 254721600 = 19992^2 + 15960^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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 17 ways as a sum of consecutive naturals, for example, 50652 + ... + 62244.

Almost surely, 2^654401664 is an apocalyptic number.

654401664 is a gapful number since it is divisible by the number (64) 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 654401664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1095372135).

654401664 is an abundant number, since it is smaller than the sum of its proper divisors (1536342606).

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

654401664 is a wasteful number, since it uses less digits than its factorization.

654401664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11627 (or 11605 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 654401664 is about 25581.2756523204. The cubic root of 654401664 is about 868.1900381684.

The spelling of 654401664 in words is "six hundred fifty-four million, four hundred one thousand, six hundred sixty-four".