64429920 has 144 divisors (see below), whose sum is σ = 222545232. Its totient is φ = 16972800.

The previous prime is 64429907. The next prime is 64429921. The reversal of 64429920 is 2992446.

64429920 is a `hidden beast` number, since 644 + 2 + 9 + 9 + 2 + 0 = 666.

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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64429921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145219 + ... + 145661.

It is an arithmetic number, because the mean of its divisors is an integer number (1545453).

Almost surely, 2^64429920 is an apocalyptic number.

64429920 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 64429920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111272616).

64429920 is an abundant number, since it is smaller than the sum of its proper divisors (158115312).

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

64429920 is a wasteful number, since it uses less digits than its factorization.

64429920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565 (or 554 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 64429920 is about 8026.8250261233. The cubic root of 64429920 is about 400.8936685710.

The spelling of 64429920 in words is "sixty-four million, four hundred twenty-nine thousand, nine hundred twenty".