1621009801 has 8 divisors (see below), whose sum is σ = 1692465984. Its totient is φ = 1549635120.

The previous prime is 1621009759. The next prime is 1621009813. The reversal of 1621009801 is 1089001261.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1621009801 - 2⁷ = 1621009673 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1621009801.

It is not an unprimeable number, because it can be changed into a prime (1621109801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22195 + ... + 61111.

It is an arithmetic number, because the mean of its divisors is an integer number (211558248).

Almost surely, 2^1621009801 is an apocalyptic number.

It is an amenable number.

1621009801 is a deficient number, since it is larger than the sum of its proper divisors (71456183).

1621009801 is a wasteful number, since it uses less digits than its factorization.

1621009801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40751.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 1621009801 is about 40261.7659945512. The cubic root of 1621009801 is about 1174.7042686561.

The spelling of 1621009801 in words is "one billion, six hundred twenty-one million, nine thousand, eight hundred one".