61809553 has 12 divisors (see below), whose sum is σ = 67156608. Its totient is φ = 56862000.

The previous prime is 61809493. The next prime is 61809563. The reversal of 61809553 is 35590816.

It is a de Polignac number, because none of the positive numbers 2^k-61809553 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 (61809563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 81928 + ... + 82678.

It is an arithmetic number, because the mean of its divisors is an integer number (5596384).

Almost surely, 2^61809553 is an apocalyptic number.

It is an amenable number.

61809553 is a deficient number, since it is larger than the sum of its proper divisors (5347055).

61809553 is a wasteful number, since it uses less digits than its factorization.

61809553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1264 (or 1251 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 61809553 is about 7861.9051762280. The cubic root of 61809553 is about 395.3834933910.

The spelling of 61809553 in words is "sixty-one million, eight hundred nine thousand, five hundred fifty-three".