1621100072 has 8 divisors (see below), whose sum is σ = 3039562650. Its totient is φ = 810550032.

The previous prime is 1621100051. The next prime is 1621100101. The reversal of 1621100072 is 2700011261.

It can be written as a sum of positive squares in only one way, i.e., 1619740516 + 1359556 = 40246^2 + 1166^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101318747 + ... + 101318762.

Almost surely, 2^1621100072 is an apocalyptic number.

It is an amenable number.

1621100072 is a deficient number, since it is larger than the sum of its proper divisors (1418462578).

1621100072 is a wasteful number, since it uses less digits than its factorization.

1621100072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202637515 (or 202637511 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 1621100072 is about 40262.8870301175. The cubic root of 1621100072 is about 1174.7260739449.

The spelling of 1621100072 in words is "one billion, six hundred twenty-one million, one hundred thousand, seventy-two".