20724221550 has 24 divisors (see below), whose sum is σ = 51396069816. Its totient is φ = 5526459040.

The previous prime is 20724221533. The next prime is 20724221561. The reversal of 20724221550 is 5512242702.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69080589 + ... + 69080888.

It is an arithmetic number, because the mean of its divisors is an integer number (2141502909).

Almost surely, 2^20724221550 is an apocalyptic number.

20724221550 is an abundant number, since it is smaller than the sum of its proper divisors (30671848266).

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

20724221550 is a wasteful number, since it uses less digits than its factorization.

20724221550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138161492 (or 138161487 counting only the distinct ones).

The product of its (nonzero) digits is 11200, while the sum is 30.

The spelling of 20724221550 in words is "twenty billion, seven hundred twenty-four million, two hundred twenty-one thousand, five hundred fifty".