61621540000 has 120 divisors (see below), whose sum is σ = 152101037088. Its totient is φ = 24566880000.

The previous prime is 61621539997. The next prime is 61621540009. The reversal of 61621540000 is 4512616.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (61621540009) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6215047 + ... + 6224953.

Almost surely, 2^61621540000 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 61621540000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76050518544).

61621540000 is an abundant number, since it is smaller than the sum of its proper divisors (90479497088).

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

61621540000 is an equidigital number, since it uses as much as digits as its factorization.

61621540000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10248 (or 10225 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The spelling of 61621540000 in words is "sixty-one billion, six hundred twenty-one million, five hundred forty thousand".