61784431 has 2 divisors, whose sum is σ = 61784432. Its totient is φ = 61784430.

The previous prime is 61784407. The next prime is 61784449. The reversal of 61784431 is 13448716.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61784431 - 2¹⁵ = 61751663 is a prime.

It is a super-2 number, since 2×61784431² = 7634631827987522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61784131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30892215 + 30892216.

It is an arithmetic number, because the mean of its divisors is an integer number (30892216).

Almost surely, 2^61784431 is an apocalyptic number.

61784431 is a deficient number, since it is larger than the sum of its proper divisors (1).

61784431 is an equidigital number, since it uses as much as digits as its factorization.

61784431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 34.

The square root of 61784431 is about 7860.3073095140. The cubic root of 61784431 is about 395.3299193093.

It can be divided in two parts, 6178 and 4431, that added together give a square (10609 = 103²).

The spelling of 61784431 in words is "sixty-one million, seven hundred eighty-four thousand, four hundred thirty-one".