1021799961 has 32 divisors (see below), whose sum is σ = 1863115520. Its totient is φ = 538970112.

The previous prime is 1021799953. The next prime is 1021800023. The reversal of 1021799961 is 1699971201.

It is not a de Polignac number, because 1021799961 - 2³ = 1021799953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1021799921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 205480 + ... + 210393.

It is an arithmetic number, because the mean of its divisors is an integer number (58222360).

Almost surely, 2^1021799961 is an apocalyptic number.

It is an amenable number.

1021799961 is a deficient number, since it is larger than the sum of its proper divisors (841315559).

1021799961 is a wasteful number, since it uses less digits than its factorization.

1021799961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415902 (or 415896 counting only the distinct ones).

The product of its (nonzero) digits is 61236, while the sum is 45.

The square root of 1021799961 is about 31965.6059069745. The cubic root of 1021799961 is about 1007.2144797800.

The spelling of 1021799961 in words is "one billion, twenty-one million, seven hundred ninety-nine thousand, nine hundred sixty-one".