1021645494 has 16 divisors (see below), whose sum is σ = 2270323440. Its totient is φ = 340548480.

The previous prime is 1021645489. The next prime is 1021645511. The reversal of 1021645494 is 4945461201.

1021645494 is a `hidden beast` number, since 1 + 0 + 2 + 1 + 645 + 4 + 9 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9459627 + ... + 9459734.

It is an arithmetic number, because the mean of its divisors is an integer number (141895215).

Almost surely, 2^1021645494 is an apocalyptic number.

1021645494 is an abundant number, since it is smaller than the sum of its proper divisors (1248677946).

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

1021645494 is a wasteful number, since it uses less digits than its factorization.

1021645494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18919372 (or 18919366 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 1021645494 is about 31963.1896718710. The cubic root of 1021645494 is about 1007.1637231918.

The spelling of 1021645494 in words is "one billion, twenty-one million, six hundred forty-five thousand, four hundred ninety-four".