61987561 has 8 divisors (see below), whose sum is σ = 62959680. Its totient is φ = 61022928.

The previous prime is 61987511. The next prime is 61987567. The reversal of 61987561 is 16578916.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61987561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61987567) 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, 16135 + ... + 19603.

It is an arithmetic number, because the mean of its divisors is an integer number (7869960).

Almost surely, 2^61987561 is an apocalyptic number.

It is an amenable number.

61987561 is a deficient number, since it is larger than the sum of its proper divisors (972119).

61987561 is a wasteful number, since it uses less digits than its factorization.

61987561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3743.

The product of its digits is 90720, while the sum is 43.

The square root of 61987561 is about 7873.2179570999. The cubic root of 61987561 is about 395.7626902656.

The spelling of 61987561 in words is "sixty-one million, nine hundred eighty-seven thousand, five hundred sixty-one".