61072981 has 4 divisors (see below), whose sum is σ = 63728352. Its totient is φ = 58417612.

The previous prime is 61072969. The next prime is 61073057. The reversal of 61072981 is 18927016.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61072981 - 2⁷ = 61072853 is a prime.

It is a super-2 number, since 2×61072981² = 7459818016452722, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61072961) 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, 1327651 + ... + 1327696.

It is an arithmetic number, because the mean of its divisors is an integer number (15932088).

Almost surely, 2^61072981 is an apocalyptic number.

It is an amenable number.

61072981 is a deficient number, since it is larger than the sum of its proper divisors (2655371).

61072981 is a wasteful number, since it uses less digits than its factorization.

61072981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2655370.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 61072981 is about 7814.9204090637. The cubic root of 61072981 is about 393.8066445425.

Adding to 61072981 its reverse (18927016), we get a palindrome (79999997).

The spelling of 61072981 in words is "sixty-one million, seventy-two thousand, nine hundred eighty-one".