61421664 has 48 divisors (see below), whose sum is σ = 166440960. Its totient is φ = 19812480.

The previous prime is 61421653. The next prime is 61421677. The reversal of 61421664 is 46612416.

It is a tau number, because it is divible by the number of its divisors (48).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7344 + ... + 13295.

It is an arithmetic number, because the mean of its divisors is an integer number (3467520).

Almost surely, 2^61421664 is an apocalyptic number.

It is an amenable number.

61421664 is an abundant number, since it is smaller than the sum of its proper divisors (105019296).

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

61421664 is a wasteful number, since it uses less digits than its factorization.

61421664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20683 (or 20675 counting only the distinct ones).

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

The square root of 61421664 is about 7837.1974582755. The cubic root of 61421664 is about 394.5546741118.

The spelling of 61421664 in words is "sixty-one million, four hundred twenty-one thousand, six hundred sixty-four".