61015920 has 80 divisors (see below), whose sum is σ = 216176640. Its totient is φ = 13946112.

The previous prime is 61015891. The next prime is 61015931. The reversal of 61015920 is 2951016.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16480 + ... + 19839.

It is an arithmetic number, because the mean of its divisors is an integer number (2702208).

Almost surely, 2^61015920 is an apocalyptic number.

61015920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61015920 is an abundant number, since it is smaller than the sum of its proper divisors (155160720).

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

61015920 is a wasteful number, since it uses less digits than its factorization.

61015920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36342 (or 36336 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 61015920 is about 7811.2687829827. The cubic root of 61015920 is about 393.6839607059.

Adding to 61015920 its reverse (2951016), we get a palindrome (63966936).

It can be divided in two parts, 6101 and 5920, that added together give a palindrome (12021).

The spelling of 61015920 in words is "sixty-one million, fifteen thousand, nine hundred twenty".