64219440 has 40 divisors (see below), whose sum is σ = 199081008. Its totient is φ = 17125120.

The previous prime is 64219361. The next prime is 64219451. The reversal of 64219440 is 4491246.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 64219398 and 64219407.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133551 + ... + 134030.

Almost surely, 2^64219440 is an apocalyptic number.

64219440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64219440 is an abundant number, since it is smaller than the sum of its proper divisors (134861568).

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

64219440 is a wasteful number, since it uses less digits than its factorization.

64219440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267597 (or 267591 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 64219440 is about 8013.7032637851. The cubic root of 64219440 is about 400.4566451563.

The spelling of 64219440 in words is "sixty-four million, two hundred nineteen thousand, four hundred forty".