1621861433 has 2 divisors, whose sum is σ = 1621861434. Its totient is φ = 1621861432.

The previous prime is 1621861393. The next prime is 1621861459. The reversal of 1621861433 is 3341681261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1471259449 + 150601984 = 38357^2 + 12272^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621861433 - 2¹² = 1621857337 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1621861393 and 1621861402.

It is not a weakly prime, because it can be changed into another prime (1621861463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810930716 + 810930717.

It is an arithmetic number, because the mean of its divisors is an integer number (810930717).

Almost surely, 2^1621861433 is an apocalyptic number.

It is an amenable number.

1621861433 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621861433 is an equidigital number, since it uses as much as digits as its factorization.

1621861433 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 35.

The square root of 1621861433 is about 40272.3407936514. The cubic root of 1621861433 is about 1174.9099512702.

The spelling of 1621861433 in words is "one billion, six hundred twenty-one million, eight hundred sixty-one thousand, four hundred thirty-three".