4021521652 has 6 divisors (see below), whose sum is σ = 7037662898. Its totient is φ = 2010760824.

The previous prime is 4021521607. The next prime is 4021521653. The reversal of 4021521652 is 2561251204.

It can be written as a sum of positive squares in only one way, i.e., 4020067216 + 1454436 = 63404^2 + 1206^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 4021521652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4021521653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502690203 + ... + 502690210.

Almost surely, 2^4021521652 is an apocalyptic number.

It is an amenable number.

4021521652 is a deficient number, since it is larger than the sum of its proper divisors (3016141246).

4021521652 is a wasteful number, since it uses less digits than its factorization.

4021521652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1005380417 (or 1005380415 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 4021521652 is about 63415.4685546042. The cubic root of 4021521652 is about 1590.2429189918.

Adding to 4021521652 its reverse (2561251204), we get a palindrome (6582772856).

The spelling of 4021521652 in words is "four billion, twenty-one million, five hundred twenty-one thousand, six hundred fifty-two".