61981431 has 8 divisors (see below), whose sum is σ = 85307904. Its totient is φ = 39987960.

The previous prime is 61981427. The next prime is 61981441. The reversal of 61981431 is 13418916.

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

It is not a de Polignac number, because 61981431 - 2² = 61981427 is a prime.

It is a super-2 number, since 2×61981431² = 7683395577615522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61981392 and 61981401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61981411) 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, 333141 + ... + 333326.

It is an arithmetic number, because the mean of its divisors is an integer number (10663488).

Almost surely, 2^61981431 is an apocalyptic number.

61981431 is a deficient number, since it is larger than the sum of its proper divisors (23326473).

61981431 is a wasteful number, since it uses less digits than its factorization.

61981431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666501.

The product of its digits is 5184, while the sum is 33.

The square root of 61981431 is about 7872.8286530319. The cubic root of 61981431 is about 395.7496440714.

The spelling of 61981431 in words is "sixty-one million, nine hundred eighty-one thousand, four hundred thirty-one".