61212733920 has 576 divisors, whose sum is σ = 233646626304. Its totient is φ = 14491975680.

The previous prime is 61212733913. The next prime is 61212733931. The reversal of 61212733920 is 2933721216.

61212733920 is a `hidden beast` number, since 612 + 1 + 2 + 7 + 3 + 39 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 181639992 + ... + 181640328.

It is an arithmetic number, because the mean of its divisors is an integer number (405636504).

Almost surely, 2^61212733920 is an apocalyptic number.

61212733920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61212733920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116823313152).

61212733920 is an abundant number, since it is smaller than the sum of its proper divisors (172433892384).

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

61212733920 is a wasteful number, since it uses less digits than its factorization.

61212733920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715 (or 704 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The spelling of 61212733920 in words is "sixty-one billion, two hundred twelve million, seven hundred thirty-three thousand, nine hundred twenty".