1020197721 has 8 divisors (see below), whose sum is σ = 1360723104. Its totient is φ = 679902080.

The previous prime is 1020197719. The next prime is 1020197743. The reversal of 1020197721 is 1277910201.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1020197721 - 2¹ = 1020197719 is a prime.

It is a super-3 number, since 3×1020197721³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1020197621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46791 + ... + 65036.

It is an arithmetic number, because the mean of its divisors is an integer number (170090388).

Almost surely, 2^1020197721 is an apocalyptic number.

It is an amenable number.

1020197721 is a deficient number, since it is larger than the sum of its proper divisors (340525383).

1020197721 is a wasteful number, since it uses less digits than its factorization.

1020197721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114871.

The product of its (nonzero) digits is 1764, while the sum is 30.

The square root of 1020197721 is about 31940.5341376753. The cubic root of 1020197721 is about 1006.6877479882.

The spelling of 1020197721 in words is "one billion, twenty million, one hundred ninety-seven thousand, seven hundred twenty-one".