15721206420 has 48 divisors (see below), whose sum is σ = 44091290880. Its totient is φ = 4185472896.

The previous prime is 15721206407. The next prime is 15721206463. The reversal of 15721206420 is 2460212751.

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 15 ways as a sum of consecutive naturals, for example, 176940 + ... + 250499.

It is an arithmetic number, because the mean of its divisors is an integer number (918568560).

Almost surely, 2^15721206420 is an apocalyptic number.

15721206420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15721206420 is an abundant number, since it is smaller than the sum of its proper divisors (28370084460).

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

15721206420 is a wasteful number, since it uses less digits than its factorization.

15721206420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428064 (or 428062 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The spelling of 15721206420 in words is "fifteen billion, seven hundred twenty-one million, two hundred six thousand, four hundred twenty".