1021021978 has 16 divisors (see below), whose sum is σ = 1556947584. Its totient is φ = 502064640.

The previous prime is 1021021909. The next prime is 1021021979. The reversal of 1021021978 is 8791201201.

It is not an unprimeable number, because it can be changed into a prime (1021021979) 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, 79951 + ... + 91837.

It is an arithmetic number, because the mean of its divisors is an integer number (97309224).

Almost surely, 2^1021021978 is an apocalyptic number.

1021021978 is a deficient number, since it is larger than the sum of its proper divisors (535925606).

1021021978 is a wasteful number, since it uses less digits than its factorization.

1021021978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12597.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 1021021978 is about 31953.4345258847. The cubic root of 1021021978 is about 1006.9587889308.

The spelling of 1021021978 in words is "one billion, twenty-one million, twenty-one thousand, nine hundred seventy-eight".