61509020 has 24 divisors (see below), whose sum is σ = 132321168. Its totient is φ = 24003200.

The previous prime is 61509017. The next prime is 61509031. The reversal of 61509020 is 2090516.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36686 + ... + 38325.

It is an arithmetic number, because the mean of its divisors is an integer number (5513382).

Almost surely, 2^61509020 is an apocalyptic number.

It is an amenable number.

61509020 is an abundant number, since it is smaller than the sum of its proper divisors (70812148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61509020 is a wasteful number, since it uses less digits than its factorization.

61509020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75061 (or 75059 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 61509020 is about 7842.7686437890. The cubic root of 61509020 is about 394.7416352416.

Adding to 61509020 its reverse (2090516), we get a palindrome (63599536).

The spelling of 61509020 in words is "sixty-one million, five hundred nine thousand, twenty".