61523551 has 4 divisors (see below), whose sum is σ = 64198512. Its totient is φ = 58848592.

The previous prime is 61523533. The next prime is 61523569. The reversal of 61523551 is 15532516.

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

It is an interprime number because it is at equal distance from previous prime (61523533) and next prime (61523569).

It is a cyclic number.

It is not a de Polignac number, because 61523551 - 2⁵ = 61523519 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 (61523951) 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, 1337446 + ... + 1337491.

It is an arithmetic number, because the mean of its divisors is an integer number (16049628).

Almost surely, 2^61523551 is an apocalyptic number.

61523551 is a deficient number, since it is larger than the sum of its proper divisors (2674961).

61523551 is a wasteful number, since it uses less digits than its factorization.

61523551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2674960.

The product of its digits is 4500, while the sum is 28.

The square root of 61523551 is about 7843.6949838708. The cubic root of 61523551 is about 394.7727176155.

The spelling of 61523551 in words is "sixty-one million, five hundred twenty-three thousand, five hundred fifty-one".