1621499743 has 4 divisors (see below), whose sum is σ = 1648081768. Its totient is φ = 1594917720.

The previous prime is 1621499741. The next prime is 1621499749. The reversal of 1621499743 is 3479941261.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1621499743 - 2¹ = 1621499741 is a prime.

It is a super-2 number, since 2×1621499743² = 5258522833098132098, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1621499693 and 1621499702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621499741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13290921 + ... + 13291042.

It is an arithmetic number, because the mean of its divisors is an integer number (412020442).

Almost surely, 2^1621499743 is an apocalyptic number.

1621499743 is a deficient number, since it is larger than the sum of its proper divisors (26582025).

1621499743 is an equidigital number, since it uses as much as digits as its factorization.

1621499743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26582024.

The product of its digits is 326592, while the sum is 46.

The square root of 1621499743 is about 40267.8499922705. The cubic root of 1621499743 is about 1174.8226062059.

The spelling of 1621499743 in words is "one billion, six hundred twenty-one million, four hundred ninety-nine thousand, seven hundred forty-three".