61213920 has 48 divisors (see below), whose sum is σ = 192825360. Its totient is φ = 16323584.

The previous prime is 61213903. The next prime is 61213921. The reversal of 61213920 is 2931216.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61213921) by changing a digit.

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, 63285 + ... + 64244.

It is an arithmetic number, because the mean of its divisors is an integer number (4017195).

Almost surely, 2^61213920 is an apocalyptic number.

61213920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61213920 is an abundant number, since it is smaller than the sum of its proper divisors (131611440).

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

61213920 is a wasteful number, since it uses less digits than its factorization.

61213920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127547 (or 127539 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 61213920 is about 7823.9325150464. The cubic root of 61213920 is about 394.1093429077.

The spelling of 61213920 in words is "sixty-one million, two hundred thirteen thousand, nine hundred twenty".