64869840 has 240 divisors, whose sum is σ = 254257536. Its totient is φ = 14515200.

The previous prime is 64869811. The next prime is 64869853. The reversal of 64869840 is 4896846.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×64869840² = 8416192283251200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a nialpdrome in base 14.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 307335 + ... + 307545.

Almost surely, 2^64869840 is an apocalyptic number.

64869840 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 64869840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127128768).

64869840 is an abundant number, since it is smaller than the sum of its proper divisors (189387696).

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

64869840 is a wasteful number, since it uses less digits than its factorization.

64869840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 64869840 is about 8054.1815226626. The cubic root of 64869840 is about 401.8040182307.

The spelling of 64869840 in words is "sixty-four million, eight hundred sixty-nine thousand, eight hundred forty".