61547551 has 4 divisors (see below), whose sum is σ = 66281992. Its totient is φ = 56813112.

The previous prime is 61547543. The next prime is 61547639. The reversal of 61547551 is 15574516.

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

It is a cyclic number.

It is not a de Polignac number, because 61547551 - 2³ = 61547543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61547501) 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, 2367201 + ... + 2367226.

It is an arithmetic number, because the mean of its divisors is an integer number (16570498).

Almost surely, 2^61547551 is an apocalyptic number.

61547551 is a deficient number, since it is larger than the sum of its proper divisors (4734441).

61547551 is a wasteful number, since it uses less digits than its factorization.

61547551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4734440.

The product of its digits is 21000, while the sum is 34.

The square root of 61547551 is about 7845.2247259081. The cubic root of 61547551 is about 394.8240438331.

The spelling of 61547551 in words is "sixty-one million, five hundred forty-seven thousand, five hundred fifty-one".