61209984 has 128 divisors (see below), whose sum is σ = 182033280. Its totient is φ = 18063360.

The previous prime is 61209977. The next prime is 61209991. The reversal of 61209984 is 48990216.

It is an interprime number because it is at equal distance from previous prime (61209977) and next prime (61209991).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181464 + ... + 181800.

It is an arithmetic number, because the mean of its divisors is an integer number (1422135).

Almost surely, 2^61209984 is an apocalyptic number.

61209984 is a gapful number since it is divisible by the number (64) 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 61209984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91016640).

61209984 is an abundant number, since it is smaller than the sum of its proper divisors (120823296).

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

61209984 is a wasteful number, since it uses less digits than its factorization.

61209984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 61209984 is about 7823.6809750909. The cubic root of 61209984 is about 394.1008957679.

The spelling of 61209984 in words is "sixty-one million, two hundred nine thousand, nine hundred eighty-four".