61651553 has 4 divisors (see below), whose sum is σ = 61974528. Its totient is φ = 61328580.

The previous prime is 61651549. The next prime is 61651559. The reversal of 61651553 is 35515616.

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 61651553 - 2² = 61651549 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61651559) 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, 161201 + ... + 161582.

It is an arithmetic number, because the mean of its divisors is an integer number (15493632).

Almost surely, 2^61651553 is an apocalyptic number.

It is an amenable number.

61651553 is a deficient number, since it is larger than the sum of its proper divisors (322975).

61651553 is a wasteful number, since it uses less digits than its factorization.

61651553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322974.

The product of its digits is 13500, while the sum is 32.

The square root of 61651553 is about 7851.8502914918. The cubic root of 61651553 is about 395.0463076618.

The spelling of 61651553 in words is "sixty-one million, six hundred fifty-one thousand, five hundred fifty-three".