1721388442 has 8 divisors (see below), whose sum is σ = 2637020736. Its totient is φ = 842381532.

The previous prime is 1721388439. The next prime is 1721388451. The reversal of 1721388442 is 2448831271.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 1721388395 and 1721388404.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9156228 + ... + 9156415.

It is an arithmetic number, because the mean of its divisors is an integer number (329627592).

Almost surely, 2^1721388442 is an apocalyptic number.

1721388442 is a deficient number, since it is larger than the sum of its proper divisors (915632294).

1721388442 is a wasteful number, since it uses less digits than its factorization.

1721388442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18312692.

The product of its digits is 86016, while the sum is 40.

The square root of 1721388442 is about 41489.6184846282. The cubic root of 1721388442 is about 1198.4675906937.

The spelling of 1721388442 in words is "one billion, seven hundred twenty-one million, three hundred eighty-eight thousand, four hundred forty-two".