1621017864 has 48 divisors (see below), whose sum is σ = 4648510620. Its totient is φ = 508554240.

The previous prime is 1621017833. The next prime is 1621017877. The reversal of 1621017864 is 4687101261.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1337364900 + 283652964 = 36570^2 + 16842^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 660957 + ... + 663404.

Almost surely, 2^1621017864 is an apocalyptic number.

It is an amenable number.

1621017864 is an abundant number, since it is smaller than the sum of its proper divisors (3027492756).

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

1621017864 is a wasteful number, since it uses less digits than its factorization.

1621017864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324390 (or 1324383 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1621017864 is about 40261.8661266464. The cubic root of 1621017864 is about 1174.7062163360.

The spelling of 1621017864 in words is "one billion, six hundred twenty-one million, seventeen thousand, eight hundred sixty-four".