61257981 has 8 divisors (see below), whose sum is σ = 81941184. Its totient is φ = 40706720.

The previous prime is 61257979. The next prime is 61258009. The reversal of 61257981 is 18975216.

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

It is a cyclic number.

It is not a de Polignac number, because 61257981 - 2¹ = 61257979 is a prime.

It is a super-2 number, since 2×61257981² = 7505080472392722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61257941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31896 + ... + 33761.

It is an arithmetic number, because the mean of its divisors is an integer number (10242648).

Almost surely, 2^61257981 is an apocalyptic number.

It is an amenable number.

61257981 is a deficient number, since it is larger than the sum of its proper divisors (20683203).

61257981 is a wasteful number, since it uses less digits than its factorization.

61257981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65971.

The product of its digits is 30240, while the sum is 39.

The square root of 61257981 is about 7826.7477920270. The cubic root of 61257981 is about 394.2038785247.

The spelling of 61257981 in words is "sixty-one million, two hundred fifty-seven thousand, nine hundred eighty-one".