61778412 has 72 divisors (see below), whose sum is σ = 162594432. Its totient is φ = 19756800.

The previous prime is 61778407. The next prime is 61778417. The reversal of 61778412 is 21487716.

It is an interprime number because it is at equal distance from previous prime (61778407) and next prime (61778417).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (61778417) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 219712 + ... + 219992.

It is an arithmetic number, because the mean of its divisors is an integer number (2258256).

Almost surely, 2^61778412 is an apocalyptic number.

61778412 is a gapful number since it is divisible by the number (62) 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 61778412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81297216).

61778412 is an abundant number, since it is smaller than the sum of its proper divisors (100816020).

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

61778412 is a wasteful number, since it uses less digits than its factorization.

61778412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 514 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 61778412 is about 7859.9244271176. The cubic root of 61778412 is about 395.3170812959.

It can be divided in two parts, 617784 and 12, that added together give a square (617796 = 786²).

The spelling of 61778412 in words is "sixty-one million, seven hundred seventy-eight thousand, four hundred twelve".