61507681 has 4 divisors (see below), whose sum is σ = 64181952. Its totient is φ = 58833412.

The previous prime is 61507669. The next prime is 61507711. The reversal of 61507681 is 18670516.

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 61507681 - 2¹⁵ = 61474913 is a prime.

It is a super-2 number, since 2×61507681² = 7566389643995522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61507181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1337101 + ... + 1337146.

It is an arithmetic number, because the mean of its divisors is an integer number (16045488).

Almost surely, 2^61507681 is an apocalyptic number.

It is an amenable number.

61507681 is a deficient number, since it is larger than the sum of its proper divisors (2674271).

61507681 is a wasteful number, since it uses less digits than its factorization.

61507681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2674270.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 61507681 is about 7842.6832780624. The cubic root of 61507681 is about 394.7387708222.

It can be divided in two parts, 6150 and 7681, that added together give a palindrome (13831).

The spelling of 61507681 in words is "sixty-one million, five hundred seven thousand, six hundred eighty-one".