61211520 has 96 divisors (see below), whose sum is σ = 211390920. Its totient is φ = 16321536.

The previous prime is 61211519. The next prime is 61211537. The reversal of 61211520 is 2511216.

61211520 is a `hidden beast` number, since 612 + 1 + 1 + 52 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 61211493 and 61211502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 447 + ... + 11073.

Almost surely, 2^61211520 is an apocalyptic number.

61211520 is a gapful number since it is divisible by the number (60) 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 61211520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105695460).

61211520 is an abundant number, since it is smaller than the sum of its proper divisors (150179400).

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

61211520 is a wasteful number, since it uses less digits than its factorization.

61211520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10652 (or 10637 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 61211520 is about 7823.7791379870. The cubic root of 61211520 is about 394.1041922558.

Adding to 61211520 its reverse (2511216), we get a palindrome (63722736).

The spelling of 61211520 in words is "sixty-one million, two hundred eleven thousand, five hundred twenty".