1621212065 has 16 divisors (see below), whose sum is σ = 2153995200. Its totient is φ = 1161462720.

The previous prime is 1621212059. The next prime is 1621212077. The reversal of 1621212065 is 5602121261.

It is not a de Polignac number, because 1621212065 - 2⁶ = 1621212001 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 216290 + ... + 223659.

It is an arithmetic number, because the mean of its divisors is an integer number (134624700).

Almost surely, 2^1621212065 is an apocalyptic number.

It is an amenable number.

1621212065 is a deficient number, since it is larger than the sum of its proper divisors (532783135).

1621212065 is a wasteful number, since it uses less digits than its factorization.

1621212065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440032.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 1621212065 is about 40264.2777781994. The cubic root of 1621212065 is about 1174.7531251368.

The spelling of 1621212065 in words is "one billion, six hundred twenty-one million, two hundred twelve thousand, sixty-five".