61212240 has 160 divisors (see below), whose sum is σ = 223378560. Its totient is φ = 15353856.

The previous prime is 61212233. The next prime is 61212247. The reversal of 61212240 is 4221216.

61212240 is a `hidden beast` number, since 612 + 12 + 2 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (61212233) and next prime (61212247).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61212247) 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, 35887 + ... + 37553.

It is an arithmetic number, because the mean of its divisors is an integer number (1396116).

Almost surely, 2^61212240 is an apocalyptic number.

61212240 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 61212240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111689280).

61212240 is an abundant number, since it is smaller than the sum of its proper divisors (162166320).

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

61212240 is a wasteful number, since it uses less digits than its factorization.

61212240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1706 (or 1694 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 61212240 is about 7823.8251514205. The cubic root of 61212240 is about 394.1057374655.

Adding to 61212240 its reverse (4221216), we get a palindrome (65433456).

The spelling of 61212240 in words is "sixty-one million, two hundred twelve thousand, two hundred forty".