61731231 has 8 divisors (see below), whose sum is σ = 82359984. Its totient is φ = 41128320.

The previous prime is 61731223. The next prime is 61731251. The reversal of 61731231 is 13213716.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61731231 - 2³ = 61731223 is a prime.

It is a super-2 number, since 2×61731231² = 7621489761550722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61731211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55 + ... + 11111.

It is an arithmetic number, because the mean of its divisors is an integer number (10294998).

Almost surely, 2^61731231 is an apocalyptic number.

61731231 is a deficient number, since it is larger than the sum of its proper divisors (20628753).

61731231 is a wasteful number, since it uses less digits than its factorization.

61731231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12921.

The product of its digits is 756, while the sum is 24.

The square root of 61731231 is about 7856.9224891175. The cubic root of 61731231 is about 395.2164193508.

Adding to 61731231 its reverse (13213716), we get a palindrome (74944947).

The spelling of 61731231 in words is "sixty-one million, seven hundred thirty-one thousand, two hundred thirty-one".