61151220 has 192 divisors, whose sum is σ = 212244480. Its totient is φ = 14515200.

The previous prime is 61151191. The next prime is 61151221. The reversal of 61151220 is 2215116.

61151220 is a `hidden beast` number, since 611 + 51 + 2 + 2 + 0 = 666.

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 = 61151193 and 61151202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61151221) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 217480 + ... + 217760.

It is an arithmetic number, because the mean of its divisors is an integer number (1105440).

Almost surely, 2^61151220 is an apocalyptic number.

61151220 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 61151220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106122240).

61151220 is an abundant number, since it is smaller than the sum of its proper divisors (151093260).

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

61151220 is a wasteful number, since it uses less digits than its factorization.

61151220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 335 counting only the distinct ones).

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

The square root of 61151220 is about 7819.9245520657. The cubic root of 61151220 is about 393.9747379167.

Adding to 61151220 its reverse (2215116), we get a palindrome (63366336).

The spelling of 61151220 in words is "sixty-one million, one hundred fifty-one thousand, two hundred twenty".