1621752001 has 2 divisors, whose sum is σ = 1621752002. Its totient is φ = 1621752000.

The previous prime is 1621751981. The next prime is 1621752017. The reversal of 1621752001 is 1002571261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 987467776 + 634284225 = 31424^2 + 25185^2 .

It is an emirp because it is prime and its reverse (1002571261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1621752001 - 2¹¹ = 1621749953 is a prime.

It is not a weakly prime, because it can be changed into another prime (1621752071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810876000 + 810876001.

It is an arithmetic number, because the mean of its divisors is an integer number (810876001).

Almost surely, 2^1621752001 is an apocalyptic number.

It is an amenable number.

1621752001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621752001 is an equidigital number, since it uses as much as digits as its factorization.

1621752001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 1621752001 is about 40270.9821211254. The cubic root of 1621752001 is about 1174.8835257415.

The spelling of 1621752001 in words is "one billion, six hundred twenty-one million, seven hundred fifty-two thousand, one".