61515651 has 4 divisors (see below), whose sum is σ = 82020872. Its totient is φ = 41010432.

The previous prime is 61515631. The next prime is 61515653. The reversal of 61515651 is 15651516.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 61515651 - 2⁷ = 61515523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61515653) 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, 10252606 + ... + 10252611.

It is an arithmetic number, because the mean of its divisors is an integer number (20505218).

Almost surely, 2^61515651 is an apocalyptic number.

61515651 is a deficient number, since it is larger than the sum of its proper divisors (20505221).

61515651 is a wasteful number, since it uses less digits than its factorization.

61515651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20505220.

The product of its digits is 4500, while the sum is 30.

The square root of 61515651 is about 7843.1913785142. The cubic root of 61515651 is about 394.7558198155.

The spelling of 61515651 in words is "sixty-one million, five hundred fifteen thousand, six hundred fifty-one".