64821880 has 16 divisors (see below), whose sum is σ = 145849320. Its totient is φ = 25928736.

The previous prime is 64821877. The next prime is 64821881. The reversal of 64821880 is 8812846.

It is a super-2 number, since 2×64821880² = 8403752253468800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64821881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 810234 + ... + 810313.

Almost surely, 2^64821880 is an apocalyptic number.

It is an amenable number.

64821880 is an abundant number, since it is smaller than the sum of its proper divisors (81027440).

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

64821880 is a wasteful number, since it uses less digits than its factorization.

64821880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1620558 (or 1620554 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 64821880 is about 8051.2036367241. The cubic root of 64821880 is about 401.7049723477.

The spelling of 64821880 in words is "sixty-four million, eight hundred twenty-one thousand, eight hundred eighty".