61539436 has 48 divisors (see below), whose sum is σ = 127475712. Its totient is φ = 25444800.

The previous prime is 61539431. The next prime is 61539449. The reversal of 61539436 is 63493516.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a junction number, because it is equal to n+sod(n) for n = 61539395 and 61539404.

It is not an unprimeable number, because it can be changed into a prime (61539431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 197721 + ... + 198031.

It is an arithmetic number, because the mean of its divisors is an integer number (2655744).

Almost surely, 2^61539436 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61539436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63737856).

61539436 is an abundant number, since it is smaller than the sum of its proper divisors (65936276).

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

61539436 is a wasteful number, since it uses less digits than its factorization.

61539436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 548 counting only the distinct ones).

The product of its digits is 58320, while the sum is 37.

The square root of 61539436 is about 7844.7075152615. The cubic root of 61539436 is about 394.8066906490.

The spelling of 61539436 in words is "sixty-one million, five hundred thirty-nine thousand, four hundred thirty-six".