61211920 has 160 divisors (see below), whose sum is σ = 187130880. Its totient is φ = 18040320.

The previous prime is 61211897. The next prime is 61211921. The reversal of 61211920 is 2911216.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 61211891 and 61211900.

It is not an unprimeable number, because it can be changed into a prime (61211921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 116779 + ... + 117301.

It is an arithmetic number, because the mean of its divisors is an integer number (1169568).

Almost surely, 2^61211920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61211920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93565440).

61211920 is an abundant number, since it is smaller than the sum of its proper divisors (125918960).

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

61211920 is a wasteful number, since it uses less digits than its factorization.

61211920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 573 (or 567 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 61211920 is about 7823.8047010390. The cubic root of 61211920 is about 394.1050507071.

The spelling of 61211920 in words is "sixty-one million, two hundred eleven thousand, nine hundred twenty".