61311487 has 4 divisors (see below), whose sum is σ = 61392816. Its totient is φ = 61230160.

The previous prime is 61311463. The next prime is 61311517. The reversal of 61311487 is 78411316.

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 61311487 - 2¹⁵ = 61278719 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61311787) 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, 39523 + ... + 41044.

It is an arithmetic number, because the mean of its divisors is an integer number (15348204).

Almost surely, 2^61311487 is an apocalyptic number.

61311487 is a deficient number, since it is larger than the sum of its proper divisors (81329).

61311487 is an equidigital number, since it uses as much as digits as its factorization.

61311487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81328.

The product of its digits is 4032, while the sum is 31.

The square root of 61311487 is about 7830.1651962139. The cubic root of 61311487 is about 394.3186180483.

It can be divided in two parts, 613 and 11487, that added together give a square (12100 = 110²).

The spelling of 61311487 in words is "sixty-one million, three hundred eleven thousand, four hundred eighty-seven".