61531619 has 4 divisors (see below), whose sum is σ = 65151144. Its totient is φ = 57912096.

The previous prime is 61531607. The next prime is 61531637. The reversal of 61531619 is 91613516.

It is a happy number.

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 61531619 - 2¹² = 61527523 is a prime.

It is a super-2 number, since 2×61531619² = 7572280273522322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61531669) 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, 1809737 + ... + 1809770.

It is an arithmetic number, because the mean of its divisors is an integer number (16287786).

Almost surely, 2^61531619 is an apocalyptic number.

61531619 is a deficient number, since it is larger than the sum of its proper divisors (3619525).

61531619 is a wasteful number, since it uses less digits than its factorization.

61531619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3619524.

The product of its digits is 4860, while the sum is 32.

The square root of 61531619 is about 7844.2092654391. The cubic root of 61531619 is about 394.7899732681.

The spelling of 61531619 in words is "sixty-one million, five hundred thirty-one thousand, six hundred nineteen".