61771531 has 2 divisors, whose sum is σ = 61771532. Its totient is φ = 61771530.

The previous prime is 61771529. The next prime is 61771547. The reversal of 61771531 is 13517716.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61771531 - 2¹ = 61771529 is a prime.

It is a super-2 number, since 2×61771531² = 7631444084167922, which contains 22 as substring.

Together with 61771529, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 61771493 and 61771502.

It is not a weakly prime, because it can be changed into another prime (61771631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30885765 + 30885766.

It is an arithmetic number, because the mean of its divisors is an integer number (30885766).

Almost surely, 2^61771531 is an apocalyptic number.

61771531 is a deficient number, since it is larger than the sum of its proper divisors (1).

61771531 is an equidigital number, since it uses as much as digits as its factorization.

61771531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4410, while the sum is 31.

The square root of 61771531 is about 7859.4866880732. The cubic root of 61771531 is about 395.3024036885.

The spelling of 61771531 in words is "sixty-one million, seven hundred seventy-one thousand, five hundred thirty-one".