61331381 has 4 divisors (see below), whose sum is σ = 62636352. Its totient is φ = 60026412.

The previous prime is 61331371. The next prime is 61331399. The reversal of 61331381 is 18313316.

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 61331381 - 2¹⁴ = 61314997 is a prime.

It is a super-2 number, since 2×61331381² = 7523076590734322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61331381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61331371) 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, 652415 + ... + 652508.

It is an arithmetic number, because the mean of its divisors is an integer number (15659088).

Almost surely, 2^61331381 is an apocalyptic number.

It is an amenable number.

61331381 is a deficient number, since it is larger than the sum of its proper divisors (1304971).

61331381 is a wasteful number, since it uses less digits than its factorization.

61331381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1304970.

The product of its digits is 1296, while the sum is 26.

The square root of 61331381 is about 7831.4354367510. The cubic root of 61331381 is about 394.3612621849.

Adding to 61331381 its reverse (18313316), we get a palindrome (79644697).

The spelling of 61331381 in words is "sixty-one million, three hundred thirty-one thousand, three hundred eighty-one".