61478731 has 4 divisors (see below), whose sum is σ = 62396392. Its totient is φ = 60561072.

The previous prime is 61478723. The next prime is 61478759. The reversal of 61478731 is 13787416.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61478731 - 2³ = 61478723 is a prime.

It is a super-2 number, since 2×61478731² = 7559268730740722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61478761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 458730 + ... + 458863.

It is an arithmetic number, because the mean of its divisors is an integer number (15599098).

Almost surely, 2^61478731 is an apocalyptic number.

61478731 is a deficient number, since it is larger than the sum of its proper divisors (917661).

61478731 is an equidigital number, since it uses as much as digits as its factorization.

61478731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 917660.

The product of its digits is 28224, while the sum is 37.

The square root of 61478731 is about 7840.8373915035. The cubic root of 61478731 is about 394.6768301529.

It can be divided in two parts, 6147 and 8731, that added together give a triangular number (14878 = T₁₇₂).

The spelling of 61478731 in words is "sixty-one million, four hundred seventy-eight thousand, seven hundred thirty-one".